Does your engine make this sound when cold?

Update: December 19, 2007:
No need to read through all the pages of this topic, Toyota has introduced a technical service bulletin to deal with this problem, number TSB2754.

A copy of the bulletin is viewable at this thread (first post).
http://matrixowners.com/index.php?showtopic=72524

To know if you have a problem requiring this solution, listen to the audio recording at the following link to shared thread containing MP3 recording, click on attachment at bottom of first post:

http://forums.genvibe.com/zerothread?id=20409

================================================== =================
Initial Post starts after following consolidated statistics, as of Dec 9, 2006

Poll results

Corolland .............Yes= 2...............No= 21...........Yes,but different sound= 2
MatrixOwners...........Yes= 9...............No= 52...........Yes,but different sound= 1
GenVibe................Yes= 11...............No= 34...........Yes,but different sound= 0
ToyotaNation-Corolla...Yes= 4...............No= 26...........Yes,but different sound= 0
ToyotaNation-Matrix....Yes= 0...............No= 15...........Yes,but different sound= 1
The creator of poll....Yes= 1
Total..................Yes= 27..............No= 148..........Yes,but different sound= 4
Grand total = 179

Percentage with identical sound = 15.1%
Percentage without sound = 82.7%
Percentage with different sound = 2.2%

While the polls are anonymous, there are posts in all these forums by owners claiming to have the identical issue.
For the purpose of identifying which models and production years are involved, they are as follows in no particular order:
There are no automatic transmissions among this group.

From MATRIXOWNERS.COM

MaidkarenD......'03..Matrix.XR......location:Illin ois
Lime............'03..Matrix.XR......location:Ontar io
PegMatrix.......'03..Matrix.XR......location:Manit oba
oracle (friend).'04..Matrix.XR......location:Ontario
Purplenv........'03..Matrix.XR......location:Ontar io
Bridgejoe.......'03..Matrix.........location:Minne sota
dominator.......'04..Matrix ........location:Ontario
Truckerbob......'03..Matrix.........location:Ontar io
chmodx..........'05..Matrix.........location:Virgi nia
TheCrispyness...'04..Matrix.........location:Illin ois
dexter..........'03..Matrix.XR......location:Ontar io
Montreal........'03..Matrix.........location:Quebe c
Ontario member..'03..Matrix.........location:Ontario

From COROLLAND.COM

BobLevine........'03..Corolla......location:North Carolina
euzeka...........'04..Corolla......location:Quebec
Ti-Jean (friend).'03..Vibe.........location:Quebec
amember..........'03..Corolla......location:Quebec
Mr.Ed............'04..Corolla......location:?
Lethal 7.........'04..Vibe.........location:Illinois

From GENVIBE.COM

Heh!heh!..........'03..Vibe.........location:Ontar io
joatmon...........'03..Vibe.........location:Maryl and
martinz...........'03..Vibe.........location:Ontar io
Andrew-4ce........'03..Vibe.........location:Ontario
burkeyro..........'03..Vibe.........loaction:Ohio
sylvainber........'04..Vibe.........location:Illin ois

From TOYOTANATION.COM (Corolla)

John2000ve........'00..Corolla......location:Texas
CorollaULEV.......'03..Corolla......location:Virgi nia
AUDI..............'03..Corolla......location:Ontar io
rated_w...........'01..Corolla......location:Ontar io

From TOYOTANATION.COM (Matrix)

Salsa03...........'03..Vibe.........location:Ontar io

Other stats

Thread Hits
Corolland................22676
Matrixowners..............6418
GenVibe...................5959
ToyotaNation-Corolla......2717
ToyotaNation-Matrix.......1738

Audio recording downloads..1165

Links to polls

http://www.corolland.com/forums/index.php?showtopic=17277&hl=montreal

http://www.matrixowners.com/forums/index.php?showtopic=38489

http://forums.genvibe.com/zerothread?id=15929


http://www.toyotanation.com/forum/t72737.html

Links to technical discussion.

http://forums.genvibe.com/zerothread?id=9403


Listen to the sound recording of my engine and please participate in the poll questions which appear at the end of this post. The recording last 20 seconds and captures an event that typically lasts about 40 seconds. This happens at least once a day in winter since my 2003 Matrix was new. Corolla and Matrix use the same engine.

Link to shared thread containing MP3 recording, click on attachment at bottom of first post:
http://forums.genvibe.com/zerothread?id=20409

It is only because Toyota head office has recently thrown in the towel that I regretably feel obliged to place my complaint in the public domain. Also, there has been some confusion as to what the sound is really like. I am pleased to offer for the first time ever a recording.

In another thread titled "idle pulses when starting", many forum members participated in a discussion aimed at finding a technical solution for a rare characteristic that affected a small number of owners in the colder climates of North America.

What we all hoped to eliminate is a unique sound that our engines make during the second minute following a startup after the cars have sat in below freezing temperatures for a minimum of 6 - 8 hours.

For the most part, this issue appears to be cosmetic. Neither drivability nor fuel economy are negatively affected. Nor do these cars pollute.

Many dealerships have made honest, but unsuccessful, attempts to find a solution.

The turning point for me was when I realized that I could pull the fuse on the engine computer and make this sound go away for 2 days at a time. I concluded that no single engine component was defective, rather that all my engine components behaved in a unique combination so as to challenge my engine computer to its limit in order to properly manage the engine when cold.

The sound you are hearing is when the engine software can no longer reconcile all its objectives regarding long term pollution control and keep the idle speed smooth at the same time.

If I were Toyota, I would not want to change the multi-million dollar software of their engine computer in order to satisfy a handfull of unlucky owners. Nevertheless, I paid a full price for my new car and did not end up with one that sounds like all the other Toyotas in my city. Toyota writes that my car is not “abnormal”. But it doesn’t sound normal to me. How about you?

Please vote in the poll and post comments which address the following:

1) how objectionable would you find this sound were your car to make it at the same frequency and for the same time duration as mine, and

2) if you were offered for sale a second-hand Corrola that made this sound, would you offer less money to purchase it, and if so, how much less money, bearing in mind that this issue is strictly cosmetic?

Thanks in advance for your participation.

.

hmmm.. I have an 89 Corolla GTS with a 4AGE motor.. now this is a 16yr old car and its got 340km on it.. well, my car used to do the same thing when it idled, it revved up and down. This started after I let Mr Lube do a throttle body cleaning, and I finally figured out how to get rid of it later on. All I had to do was find the idle adjusting screw and turn it up first to make the car rev steady at about 2000rpm.. then I gave it a few seconds and turned the screw down to lower the revs until they were at a steady 900-1000rpm, which is practically normal for a 4AGE. Before doing this.. my motor would go from 1500rpm and jolt to like 2000rpm then back down to 1500rpm. Of course this only happened when it was cold out and it didn't when it was hot.. it went away after the adjustment and never came back.

Try this with your car, hopefully it will work. :)

finally figured out how to get rid of it later on. All I had to do was find the idle adjusting screw and turn it up first to make the car rev steady at about 2000rpm.Try this with your car, hopefully it will work. :)
Unfortunately my car doesn't have an adjusting screw to better control the idle bypass air supply.

It is the computer that controls the Idle Air Control valve directly.

I think the computer is just ordering too much gas to be injected for some mysterious reason. Then it gets all upset because it sees the rpms climb higher than it predicted.

Thanks anyway for the suggestion.

NP hope you get your problem fixed.. sounds like the ECU is malfunctioning or miscalculating anyways.

NP hope you get your problem fixed.. sounds like the ECU is malfunctioning or miscalculating anyways.
That's what I think.

The problem is that the calculations are already optimized so that the millions of Toyotas in North America pass the pollution tests.

Toyota is not going to alter this program so that a few hundred owners like myself with marginal engine components can be saved. The risk of unforeseen sideeffects from a program change is too great. I certainly wouldn't touch the program if I was them.

Ok I have to ask a few questions first. The sound I hear sounds like the cycling of increasing and decreasing engine RPM. Is that the issue you're reporting?

Now I didn't see any info on what year and version of Matrix you have? What's the mileage? Have you made any modifications to engine, exhaust, drivetrain? Have you kept up with mainteance? This info might be important - I've seen wonky automatic transmission issues cause because someone when 25k on a single oil change. (wtg Mazda!). Now there are enough differences in parts between Corolla and Matrix to make them distinct cars so it's tough to know where to start.

Have you contacted Toyota Canada at 1-888-TOYOTA-8 and spoken to someone in their Customer Relations department? Do this yourself - don't let a dealer do this.

With the exception of the dealer...has your car been inspected by someone from Toyota Canada head office (ie: has someone from Toronto come out to see the car...or was it shipped to Toronto for inspection?).

Are there any engine codes generated?

I hear some bubbling sound in the audio file. I think that is what you are trying to point out. My 1ZZ (same as your Matrix engine) Corolla S did not have any bubbling sounds like that. It does not seem normal. You will have to get it checked out by a mechanic at your Toyota dealership.

I don't hear anything unusual - except for the non-OEM exhaust.

The bubbling sound is something I never heard before?? :confused:

Ok I have to ask a few questions

1) The sound I hear sounds like the cycling of increasing and decreasing engine RPM. Is that the issue you're reporting?
2) what year and version of Matrix you have?
3) What's the mileage?
4) Have you made any modifications to engine, exhaust, drivetrain?
5) Have you kept up with mainteance?
6) Have you contacted Toyota Canada at 1-888-TOYOTA-8 and spoken to someone in their Customer Relations department?
7) With the exception of the dealer...has your car been inspected by someone from Toyota Canada head office ?
8) Are there any engine codes generated?Answers:

1) Yes, those are the engine rpms that you hear when the car is idling, and only during the second minute, following a cold start with no one touching the gas pedal.
2) This is a 2003 base model Matrix with option package B (A/C).
3) The current mileage is 51 k kilometers ( 32 K miles) but the problem started the first week I brought the car home new in February 2002.
4) No modifications.
5) All scheduled maintenance done by the dealer.
6) I sent at least 4 e-mails to Toyota Canada (often to a contact person as opposed to the general mail box). Their responses thanked me for my submissions and said that my messages were being forwarded to the department concerned. One response said that there had not been other complaints similar to mine.
7) No Toyota person other than my Toyota dealer has looked at the car.
8) No engine codes were noted in all of the three scans taken.

As I have said many time since I discovered that I can make the problem temporarily go away by resetting my ECU computer memory, this is a software bug which only surfaces on a handful of vehicles that have many engine components on the borderline of being out of spec. The computer considers it a higher priority to minimize pollution than to provide a cosmetically smooth idle when cold.

Additionally. my car was inspected last month by an independant garage owned by a famous ex-rally car driver and popular local print and radio journalist. All his head mechanic could say was that the front O2 sensor is not operating during the second minute following a cold start. My O2 sensor had been changed during the first failed attempt (last February) by my dealer to fix the problem. Toyota head office refused to answer the following 3 questions:

"If you felt it necessary to change the O2 sensor because you felt that it might be causing the problem, wouldn't you appreciate knowing that the replacement sensor does not perform any better?" and
"Perhaps the O2 sensor plays no role during the second minute and you needlessly changed my sensor?", and
"At what point does the computer start monitoring the O2 sensor?"

Thanks for your detailed interest. I am more concerned in having your legal opinion about this unfixable cosmetic defect.

My 1ZZ (same as your Matrix engine) Corolla S did not have any bubbling sounds like that. It does not seem normal.

You will have to get it checked out by a mechanic at your Toyota dealership.This was done twice and the technical support people at Toyota head office have written that my engine is "not abnormal". All this happening within the 3 year warranty period for a problem that started the first week after I bought the car.

My dealership service manager suggested that I should be able to live with this cosmetic problem.

The overwhelming response in this and three other similar threads is claiming that most people would not buy a second hand Toyota which makes this sound even with the assurance that the noise is not the sign of anything wrong with the motor.

The purposes of this poll is to measure the degree of public opinion in preparation for a Class Action Law Suit.

Thanks for your answer.

I don't hear anything unusual - except for the non-OEM exhaust.
What is unusual is that fewer than one car in a thousand (by my estimation) will make this sound when cold with no one touching the gas pedal. And the exhaust is what came from the Toyota assembly line in Cambridge Ontario. The whole car including the exhaust is OEM.

my car has a REALLY crappy idle at start.. and it goes away when my cpu is reset too.. I have an 01 btw.. but the thing is it idles too low :confused: :confused:

my car has a REALLY crappy idle at start.. and it goes away when my cpu is reset too.. I have an 01 btw.. but the thing is it idles too low





OK, If I understand you, you are saying that after you reset the cpu, the car will cold idle at a reasonable steady rpm (say between 1400 and 2000) but after a few days, the cold idle becomes lower and the smoothness disappears because the idle is too low?



If true, we may be suffering in the same way.



In my case, my cpu learns to increase cold idle speed unreasonably when faced with a set of marginal engine components that suggest that the injection volume should be increased.



In you case, I suspect, your cpu learns to decrease the cold idle speed unreasonably when faced with a set of marginal engine components that suggest that the injection volume should be decreased.

I say marginal in these cases because there is a remote chance that all the sensors in a car can be within spec, but they are all biased in the same direction and these biases don't cancel out as in the majority of cars.



As I believe in the inevitability that one in ten thousand cars could sound like mine, thanks to you, I now believe that one in ten thousand cars would sound like yours.



What we have in common is a computer that trusts too much what some engine sensors might be falsely reporting and when faced with a dilemma, the cpu must make choices that reduce pollution as a priority over a smooth idle which can be seen as a cosmetic issue.



My cpu deals with over-revving by momentarily shutting down the fuel.



Does your cpu deal with an under-revving problem by momentarily increasing the rpms? If so, are there pulses that you hear? How many pulses over how many seconds and how soon after a cold start?

How soon after your purchase did this problem begin? First winter?

What was your experience getting the dealer to improve the situation if it was under warranty?

Do you believe that you will experience difficulty in reselling your car because of the way it sounds?

Have they replaced the ECU?

In any event, let me be clear on this. Forget email. Would you let the plumber diagnose your flooded basement by email? Probably not! :lol: So when it comes to your car and the dealer throws up his/her hands, leave the marvels of technology behind and speak to a live human "bean" and call...

1-888-TOYOTA-8

Tell them your problem.
Tell them what's been done to the vehicle.
Ask them what they're system says has been done. (FYI any work you've had done to the car should be in their system).
Tell them how you temporarily resolve it.
Offer to give them that wave file.
Above all...Be polite.

Keep in mind that the person you speak with is just a first line representative and will just take your info and likely escalate it to their Customer Relations issues team...expect a call within a few days with further questions and help. Be patient...they will call. Trust me.

But this is an oddity.

As for the chap with the previous gen 2001 Corolla having odd idle...has that always been like that since day one...or just with wear? What's the mileage? Too many problems. Heck my 95 Civic did that when I hit over 100K - swaped out the plugs and voila - fixed.

Have they replaced the ECU?

So when it comes to your car and the dealer throws up his/her hands, leave the marvels of technology behind and speak to a live human "bean" and call...

1-888-TOYOTA-8

No, they haven't replaced the ECU and they aren't likely to,

It is not my dealership service manager who has thrown up his hands. He said he would be more than happy to take my money to finance the replacement of every sensor in my engine until the problem goes away.

It is Toyota head office speaking through my service manager who has said that they will not pay more than the $500 that they have already spent under my warranty.

Why, because head office (TAS) has looked at the scan readout from my ECU and concluded that there is no obvious single sensor malfunctioning. Since the vehicle is drivable (it most certainly is) and since it does not pollute, they (head office) feel my case is no longer worthy of having money spent on it.

I can accept all that.

What I can't accept is my service manager's belief that I will not suffer from a loss when reselling the car because , and I quote "many people have bought second hand Chrysler minivans knowing that their transmissions are fragile and in the case of your Toyota, there is nothing broken".

He may be right, but from the responses posted in this and three other threads auditioning my sound recording, the vast majority state that they would not buy my car.

That is why I need your answers (in support or not) to my 2 poll questions much more now than another round of knocking at Toyota's backdoor.

Please, let's turn the page on trying to find a technical solution. I need a legal one now.

Thanks

montreal...dude! When you bought your car, did you really think that the sales person was going back to the Sales Manager to confirm that he can give you the car at price "X"? I hope not...because they were probably talking about the weather, or checking out LaPresse, or some BS like that. Don't take this dealers advice as gospel.

Screw the dealer - find a new one. There's easily 10 or more in Montreal. They sound like total dicks anyways...there is no such limit of $500 of warranty repairs. Frig...which dealer is this anyways? That pisses me off. The service manager is quoting you some lame party line on anything that is questionably a warranty repair. So stop dealing with that lame ass dealer and go directly to the source!

Call Toyota directly!!

Until you can demonstrate that you have dealt directly with Toyota (via their Customer Relations Department in some fashion, CAMVAP will do nothing for you...and the courts will kick it back to you to allow Toyota to resolve it. You will spend lots of $$ and time and agravation getting no where.

When my dealer screwed me around, I called Toyota. I now have a new dealer...and a car that works. Case closed.

So...Call Toyota. I cannot stress this enough. Call Toyota...I will keep saying that until you do that and let them resolve it.

Call Toyota. Just call.

So...Call Toyota. I cannot stress this enough.
Call Toyota...I will keep saying that until you do that and let them resolve it.
Call Toyota.
Call. Just call. I mean it! Call :lol::deadhorse

I'll call 1-888-TOYOTA-8

I'll tell them rolla-XRS sent me.

Thanks

Montreal, do you not watch the Simpsons? Surely it's translated into x million languages including Canada's 2 official ones. Now that's one of the failings here...I have no idea about your age/gender/etc so having read your post I can understand that perhaps you are not a Simpson's fan.

I'm sorry if you were offended. It was not my intention to offend you, but rather to CHEER you on that you finally decided to choose the course of action which will give you the best result...even after you ignored my first piece of advice. Perhaps you missed the first piece...which is why I continued to give you that same advice and be verbose about it....so it could not be missed. Now if I had lost my cool, you would know it. But I neither have the time or patience to waste in flaming anyone. Besides, we're all family here anyways so why would I flame someone? If you stick around long enough...you'll realize that.

Now - complaining to TN management doesn't solve problems here. It just escalates them and ticks people off. They don't want to moderate this place anymore than you or I would. You could have brought your issue to me via a PM first. Had I known you were offended, I would have simply removed/edited the post - no questions asked.

I hope Toyota Canada resolves your issue. I really do. There is no ramification for you to call Toyota - legal or otherwise. And if you consult with a lawyer, they will (hopefully) tell you the same if they are honest. In any event, I hope you stick around here because this place is THE place for Toyota enthusiasts - bar none!! :thumbup:

Because of your concerns I have removed/edited the above post(s). I trust you will do the same to yours and we can get back to respect and decorum.

Cheerio!!

Now where did I put my beer...<sigh>

Montreal, do you not watch the Simpsons?
I hope Toyota Canada resolves your issue.I don't watch the Simpsons but I did learn a few of Homer's famous quotes yesterday.

I do appreciate you clearing up the air because it confirms to me your good intentions and it renews my confidence in your idea, because new ideas that may work are what I really need now.

You are a great asset to this internet forum and I hope many members will continue to profit from your advice.

Of course you never know if the person you are posting to is the great grand mother of your best friend, or a student. So interpretations and reactions are bound to vary. I'll try to be more conscious of this reality in the future.

I have deleted the ambiguous post in question.

Best wishes.

Thanks!! :grouphug:

bump,

Annyone want to vote in my poll.

Thanks

1) how objectionable would you find this sound were your car to make it at the same frequency and for the same time duration as mine
VERY objectionable !!! Somethin' ain't right !!!
2) if you were offered for sale a second-hand Corrola that made this sound, would you offer less money to purchase it, and if so, how much less money, bearing in mind that this issue is strictly cosmetic?
Yes, MUCH less $$$.....sorry, that's more than a "cosmetic" issue....a scratch or small ding is "cosmetic"....cosmetic, it ain't !!! Sorry....:sosad:

VERY objectionable !!! Somethin' ain't right !!!I agree,

It sounds to me like there's a vacuum or fuel injector leak that is not bad enough for the ECU to throw a code but still bad enough to create an idle rpm that upsets the ECU.

Thanks for yor vote.

Sorry to hear that the dealers can't find the problem! I had the same exact problem in a totally different car, and it was a faulty IAC... but that was a Camaro :lol:

Sorry to hear that the dealers can't find the problem! I had the same exact problem in a totally different car, and it was a faulty IAC... but that was a Camaro :lol:Just like a vacuum leak, a faulty IAC has the effect of introducing more air into the cylinders than the ECU would prefer. In order to make sure that the burn is not too lean as a result of the extra air, the ECU has to squirt in more gas. Having that extra air and extra gas burning makes the engine turn over faster. When it becomes too fast, then the ECU has no choice but to pull the plug and cut gas and ignition until things slow down. And then start all over again.

Thanks for you response and I hope you voted.

Hey montreal, have you heard back from Toyota Canada yet? Just curious if they're helping you out yet.

Hey montreal, have you heard back from Toyota Canada yet? Just curious if they're helping you out yet.My original salesman asked me to have my car evaluated by his department in consideration of an exchange towards a new identical '05 model. I have prepared figures that take into account my ususal long term depreciation having already owned and resold a Corolla wagon which had a purchase price almost identical to that of current '03 Toyota expressed in constant dollars.

I have also factored in an allowance for major repairs such as brakes, tires, battery and timing belt, these being what I had to replace on my 1994 Corolla wagon during the 8 year period.

I know you would like me to call 1-888-toyota-8 for a technical solution.

But before I do that, I believe that I should give my salesman the chance to make a deal where I lose the least.

In the mean time, I am posting the following response from my service manager in reply to my original enquiry of Feb 24, 2005.

Dear Mr. Montreal,
I did receive your e-mail and forwarded it to our T.A.S. department.

Like I had mentioned before at this point Toyota doesn’t consider this

situation to be abnormal and are not investigating any further.

I also gave the info to Mr. R. the technician who had worked on the car for

personal information.

Thank you.

Mr. B.

That's good to hear. As long as you're happy there's progress occuring...and since you have emails and stuff for papertrail then you're okay.

Cheers!

Do not worry, I am with you. After have many troubles with two Ford Taurus (89 and 2000), I bought a 2000 Corolla VE with 83K miles on her clock about 4 months ago, it has the same sound just after startup (the bubble sound, lasted about 1 to 2 min), but it runs perfect after engine warm up. I lived in Texas, it is very warm here now, but it still make that sound every morning. however, I can live with it, maybe because I got used with my trouble making Traurus. be satisfied and happy with your rolla, you have the best car in the world!

however, I can live with it, maybe because I got used with my trouble making Traurus. be satisfied and happy with your rolla, you have the best car in the world!From your response, I will assume you are one of the very few participants in the poll who would be willing to buy my car second hand for the same price as would be the case if the noise did not exist.

This noise may be nothing more than a symptom of a beneign situation in the motor. My good gas economy may prove this out.

Or the noise may be the symptom of an air leak or an injector leak. If so, I may have one of my cylinders running overly lean or overly rich while the computer does its best to get the total performance for all four cylinders within target.

Most mechanics observing this car for the first time would probably conclude that there is a leak, because there are frequent mentions throughout the internet of the relationship between an unusually high idle and an air leak.

It is not knowing for sure that spooks most buyers. I know I would still be reluctant to buy my car second hand in spite of what I have come to understand about it's character.

I would simply prefer to have a car that idles like the other 99.9% out there.

I have posted the combined results from all polls on different forums at the top of the first post in this thread.

It appears that no more than 8% have this issue.

Now that both the cold weather and my idle hunting are back, I am bumping the thread.

I have heard of this problem occuring on an ECHO as well.

The MP3 recording referred to in the first post of this thread is again available for auditioning. The recording is now hosted on the GENVIBE forum and requires a link to the post and click on the attachment.

Now that both the cold weather and my idle hunting are back, I am bumping the thread.



I have heard of this problem occuring on an ECHO as well.



The MP3 recording referred to in the first post of this thread is again available for auditioning. The recording is now hosted on the GENVIBE forum and requires a link to the post and click on the attachment.

I'm bringing this thread back from the dead, again. But it's only because I'm interested and have a small amount of input, here.

I have a 2003 Corolla CE 5-spd. I have come to the conclusion that these engines are VERY twitchy in cold weather - at least mine is.

1) I get lots of piston slap or rod knock or whatever it is (dealer said piston slap). Whatever, I can deal.

2) This car has seen some really odd idling problems in cold weather. My situation is a bit different. Temp is around 32 deg. F (0 deg C), I start engine, allow oil pressure to climb to 80psi or so (normal cold idle pressure - about 5 seconds), I pull out and drive the car about 2 miles. At this point, coolant temp is around 100-120 deg. F. Press the clutch in, and whereas I would expect a high idle still, I have the opposite. Instead, I get a VERY, VERY low idle and incredible misfiring which I've never heard the likes of out of this car. The engine was idling at around 500rpms, and VERY roughly. Odd...otherwise, the car was running great while at speed. I sat at the stop sign I was at for about a minute and it continued to do this. A car came up behind me, so I pulled out, drove another 5 miles (by this time, I'm at around 170 deg. F). The engine was still idling VERY, VERY rough. I have a PDA with Digimoto and the Elmscan to link up to the OBD-II port and read sensor data. I watched the long-term fuel trim jump to 26% within about 15 seconds while idling (typical is around -5 to +5%). I was also showing a PENDING error code P0442 - evap leak (small leak). Bizarre. Somehow, someway, the car had developed an evap leak, which caused a lean mixture, therefore causing the ECU to increase injection by 26% (only @ idle, though). I parked the car for a few hours, and took it out later in the day. I drove a few miles down the road, and once it was warmed up and in closed loop, I watched the long-term fuel trim drop back down to its normal 2% while idling at a fuel station. I eventually cleared the pending error code and it has never came back. Oh - and it wasn't a loose fuel cap, I checked it. Loose fuel caps cause a P0440, 0442, and 0443 together, typically and they are all ACTIVE codes with the MIL ON. This code was only PENDING, with the MIL OFF.

Since that time, the engine has experienced the bizarre idling problem 2 more times. However, I didn't have the PDA to check fuel trims at the time. After the fact, I checked for error codes and there were none. It only seems to occur when I start the engine and drive off immediately, rather than letting it idle to warm-up. Otherwise, I tend to think it idles a bit too high when cold (sometimes as high as 2500rpms+).

I think you need to start pinching some hoses off under the hood while it's doing this bizarre stuff. Pinch off the EVAP hoses, the PCV hose and breather hose, one by one or in combination to see if just perhaps one of them could be at fault. They all have the potential to create a rich or lean mixture (probably lean). These cars are rather prone to charcoal canister failure and other EVAP problems. Even though I don't THINK the ECU activates the EVAP valves until it's in closed loop, I may be wrong about that. It could point you into a direction, at least. Hope this helps.

Trav

I have the exact same problem on my 2003 Corolla manual CE (w/65k on it.)

Every winter this happens when left over night in cold weather. The messed up idle sounds so painful for the car, any idea if it would have long term damaging effects?

Normal idel is a constant 2000-2100rpms.... This problem makes mine rev quickly to around 2300-2400 then drop suddenly to 1800-1900... then repeats, the same as your mp3 clip.

Should i even bother taking it to the dealership? since my warentee is up and you didnt seem to have any luck.

Maybe ill phone Toyota direct tommorow and talk to them about the problem.


Keep us updated!

.............Since that time, the engine has experienced the bizarre idling problem 2 more times. However, I didn't have the PDA to check fuel trims at the time. After the fact, I checked for error codes and there were none. It only seems to occur when I start the engine and drive off immediately, rather than letting it idle to warm-up. Otherwise, I tend to think it idles a bit too high when cold (sometimes as high as 2500rpms+).

I think you need to start pinching some hoses off under the hood while it's doing this bizarre stuff. Pinch off the EVAP hoses, the PCV hose and breather hose, one by one or in combination to see if just perhaps one of them could be at fault. They all have the potential to create a rich or lean mixture (probably lean). These cars are rather prone to charcoal canister failure and other EVAP problems. Even though I don't THINK the ECU activates the EVAP valves until it's in closed loop, I may be wrong about that. It could point you into a direction, at least. Hope this helps.

Trav

Thanks for your suggestions.

We have to remember that at any time when the ECU detects that the TPS is at the idle position, the ECU will take over the control of the engine speed using the IAC valve. The ECU will throw a code if the requested engine idle speed differs greatly from the delivered idle speed.

So if we are experiencing one of your two situations whereby under some circumstances the idle engine speed is either very low (500 rpms) or very high (2500 rpms) or my situation (pulsing between 1800 and 2300), and with no codes being thrown, then we can reasonably assume that these abnormal idle engine speeds are exactly what the ECU wants.

Another thing to remember is that the idle engine speed does not change by altering the richness of the mixture. At any time there is only so much oxygen and fuel entering the engine, and if we accidentally add more fuel without adding more air, or accidentally add more air without adding more fuel, then the number of CH molecules that will combine with the number of O2 molecules will remain the same and the heat energy being produced will remain the same and the engine speed will remain the same.

So for the engine speed to be increased, the ECU must make an effort to increase both the air being admitted to the motor and the fuel being injected. Contrary, for the idle engine speed to be reduced, the ECU need only reduce either the air or the fuel or both to achieve this.

If an unmetered air leak spontaneously becomes larger, then the idle engine speed is not going to change. For this reason, I doubt if a minor leaning of the mixture brought about due to an unmetered air leak during open loop operation is going to result in the engine speed being reduced. As well, if an unmetered air leak suddenly becomes smaller, then the idle engine speed will be reduced, but the ECU will immediately open the IAC valve to compensate for the drop in the desired number of revs. If you don't have a code saying your revs are too low at idle, then your IAC valve must be working and delivering the exact idle speed that the ECU is demanding.

I think that for the cold idle speed to be reduced to 500 as in your case, the unmetered leak would have to be so great that much of the fuel injected would not burn in a cylinder with such an oversupply of oxygen (extreme dilution).

Also, the speed should not change should the cannister suddenly dump a whole lot of vapor in open loop mode, creating an overrich situation. If the oversupply of vapor is d\so great, then the engine fill flood and stall.

If necessary, the ECU will close the IAC valve if an unexpected amount of air and fuel both arrive at the same time. No code means all is still under control.

Lastly, in my situation of pulsing, the problem goes away whenever the ECU is reset.
The pulsing returns 2 days later after a period during which the ECU discoveres that the readings reported by the many sensors don't explain the O2 sensor readings.

My belief is that no one sensor is off by alot, but that my engine has many sensors that are all off by a little, and that they are all biased in a very unique combination (like never winning the lottery), a combination of readings that is outside the ECUs ability to cope. The ECU no longer knows what is best and blindly orders an inappropriate idle speed which is ultimately delivered.

Has what I have just written strengthened or weakened your theory? Either way, we would like to know how all this is making you think.

......The messed up idle sounds so painful for the car, any idea if it would have long term damaging effects?

Should i even bother taking it to the dealership? since my warranty is up and you didn't seem to have any luck.

Maybe i'll phone Toyota directly tommorow and talk to them about the problem.


Keep us updated!

In the case of my wife's friend's ECHO, the dealer signed a document saying that whatever is causing this noise, that mysterious something will not cause the engine to suffer in any way. This brought comfort to that Echo owner.

For me to feel comfortable, I would need a document signed from Toyota acknowledging that my car will have a lower resale value in a private sale once the noise has been disclosed.

Ideally, Toyota would compensate me for the net loss versus the trade-in value at a Toyota dealership, which will not discount the value of any car with this noise, but will nevertheless give me less trade-in value than a private sale.

Whether justified or not, 95% of the public responding in these forums, has said that they do not want to own cars which make this noise. Toyota simply does not understand the gavity of this situation which can be only be corrected through an engineering effort that will cost in my estimation many millions of dollars for anti-pollution recertification.

P.S. Be sure to vote in the attached poll as the results may help get action one way or another.

I had a 1990 Camry 3S-FE before my Corolla now. This engine did have an idle adjustment screw on the TB. Cranking the idle speed way up would yield the exact same problems you're describing. The higher the idle speed was cranked up, the faster the cycling would be (low-hi-low-hi) in rpms. Obviously, the ECU attempting to maintain a target idle speed, but also trying to maintain an economical mixture - it simply wasn't possible with the air bleed being opened so far.

Alternately, the fuel pressure regulator went out on it also - however, this time, it was dumping way too much fuel. Again, same thing. Idle hunt with the low-hi-low-hi rpm searching. You could actualy hear the injectors tick, engine would rev up, then the injectors would become silent (ECU decreasing or stopping injection duration), engine rpms would lower, only to return high and cycle back low. Again, an attempt to achieve a target idle speed while maintaining a proper mixture.

A small air leak would cause idle-up - the larger the leak gets, the higher the engine will idle, however at a point, you are right, the mixture will become so diluted that it can only barely support combustion and we'll see a idling-down. Just pull the PCV hose and cap your finger over it while slowly making the hole bigger...you'll see it in action. Raising the A:F ratio (more air) will yield more heat energy - 14.7:1 is certainly not best for power. Best power is achieved with a lean mixture since ALL of the fuel is consumed during combustion with the over-supply of oxygen readily available - higher combustion temps since fuel atomization absorbs heat energy before combustion, etc. I think we agree on some aspects, here. I'd be really curious what your car would do if you started pinching some hoses while it was doing this - play around with the PCV and EVAP hoses and see what happens. Let us know what happens. Do some experimenting - send some butane through the air intake while it's doing this to see what happens - if it gets worse, then you can suspect that it's a rich-running problem. Pull the air hose up and put your hand over the air tube to choke it a bit - if it gets worse, then it's likely a lean-running problem. Play around with it a bit and see what you can discover.

Trav

.......... Do some experimenting - send some butane through the air intake while it's doing this to see what happens - if it gets worse, then you can suspect that it's a rich-running problem. Pull the air hose up and put your hand over the air tube to choke it a bit - if it gets worse, then it's likely a lean-running problem. Play around with it a bit and see what you can discover.

Trav

Thanks for the suggestions. Again, I think the pulsing is related to a fault that takes the ECU at least 2 days to fully react to. So if the fault is a leak in one of the hoses, then if I do what you suggest, I would have to reset the computer, pinch off one of the hoses, then wait 2 days to see if the ECU re-creates a pulsing situation.

Also to note is that we had my engine a number of times on a scan machine while the engine was pulsing and we could see nothing wrong with the parameters in the recording, although we could not capture all of the parameters at the time.

One of the reasons I am a reluctant to play with any of the hoses is that I don't personnally own a scan machine to reset any code that I might create by playing with the hoses. I know some codes will reset automatically with time, others won't. I don't want to pay money yet to keep my ECU clean for the dealer's sake, as I am still in a delicate situation with the manufacturer who has agreed in writing to embark on a search for a solution.

But I agree that what you are saying makes sense.

In the mean time, can you tell me if the ECU has any way of determining if the PCV hose/valse and the EVAP hose/valse are functioning properly, that is to say, if I plug either one of these hoses which will make it appear that either valve is no longer functioning, will the ECU detect a change and potentially throw a code?

It been a while since I looked at the list of codes for this engine.

A PCV fault will only show up in the fuel trims. PCV function is not controlled by the ECU, and it really has no way of checking it. If you have something dysfunctional about it, then you'll get a code for a rich or a lean condition. PCV flow is calculated into the injection duration maps. Plugging one of these hoses MIGHT cause a fault code as 70% of blow-by gases are unburned fuel, so you might get a fault code for a lean mixture.

The EVAP valves aren't operated at all until the ECU enters closed loop. Aside from the pressure sensor in the tank, the only way the ECU has to know if the EVAP system is doing its job is by watching the O2 sensor readings when it starts purging fuel vapors into the manifold. EVAP function is something that's also calculated into injector duration. With X amount of purge flow, the ECU will back off of the injector duration, and the O2 sensor readings should remain mostly the same as what they were before the purge command is sent to the VSV's. So, the EVAP valves should NOT be energized at all until you reach operating temp. If you pinch one of these hoses off permanently, you will DEFINITELY get a fault code, as the ECU tests the EVAP system every drive cycle.

What I am suggesting: when the engine is idling and doing this crazy idling up and down stuff, pinch some hoses off while it's doing this and see if anything makes a difference. EVAP shouldn't make any difference, as the EVAP system isn't energized or tested until you reach operating temp. There is slight PCV flow (there's not much blow-by under low-load conditions like idling). Alternately, lift up the airbox and place your hand over the air hose to choke it off a little. If you do throw codes, then all you have to do is pull the EFI 15A fuse in the under-hood fusebox to reset the codes (and make your bizarre idling go away for a few days). I'm not saying to reset the ECU and permanently pinch off a hose or choke the air hose some....do these things WHILE the engine is doing this bizarre idling - if something you do changes the way it's idling, then it can clue you in to what the problem may be. Does this make sense??

Do you know what kind of fuel trims your ECU is spitting out?? Long-term FT should be -10% to +10%.

Have you tried cleaning the TB out good with some carb cleaner? How about removing the PCV valve and cleaning it with some carb cleaner and verifying that it is indeed still good (or just replacing it altogether) - if the PCV valve gets crudded up, it'll remain open and allow too much recirculation (rich mixture). To check for vacuum leaks, get a propane torch and just open it up (without lighting it of course) and try aiming it around the intake manifold gasket and throttle body gasket or around the MAF sensor to see if the idle changes. It could very easily be something within the programming of the ECU, but it could also be a problem that's only there during cold operation (stuff contracts when it cools down and could easily create a leak somewhere that fixes itself once warm a little bit). If you have the chance to get back to a scanner, I would really focus on the MAF sensor readings - scrap the O2 sensor readings, as they are no good for at least a few minutes of operation until it heats up.

I'd agree that it is most likely in the ECU programming that's causing this, but it couldn't hurt to fiddle around with it a bit - you might find something more.

Now that I think about it - after I'd had my Corolla for a few months, I started it one cold morning and went into the house, then came back outside to hear it doing this bizarre idling. It only happened like twice, but mine has done this before (hasn't done it since then, though). Kind of scared me at the time. I never knew what made it do that.

Trav

.... Plugging one of these hoses MIGHT cause a fault code as 70% of blow-by gases are unburned fuel, so you might get a fault code for a lean mixture.....If you pinch one of these hoses off permanently, you will DEFINITELY get a fault code, as the ECU tests the EVAP system every drive cycle.


Since the pulsing seems to be a learned response, I truly believe that I would have to pinch off the hoses over a long period to force the ECU to unlearn the suspected air leak.


What I am suggesting: when the engine is idling and doing this crazy idling up and down stuff, pinch some hoses off while it's doing this and see if anything makes a difference. EVAP shouldn't make any difference, as the EVAP system isn't energized or tested until you reach operating temp.....
.....I'm not saying to reset the ECU and permanently pinch off a hose or choke the air hose some....do these things WHILE the engine is doing this bizarre idling - if something you do changes the way it's idling, then it can clue you in to what the problem may be. Does this make sense??

Either the ECU has learned about the suspected air leak over time and eventually creates the pulsing, or the ECU learns about some other condition over time and in conjunction with a suspected air leak, so begins the pulsing. If the later is true, then your idea of pinching off the hose(s) during pulsing might reveal new clues.


There is slight PCV flow (there's not much blow-by under low-load conditions like idling). Alternately, lift up the airbox and place your hand over the air hose to choke it off a little.

It would be easier for me to not have to pull off any hoses with their clamps, just pinch them with vice-grips. However I must appreciate that the suspected air leak may be occuring under the hose clamp so sealing the hose nipple with my finger might be a more reliable way to do this test.


If you do throw codes, then all you have to do is pull the EFI 15A fuse in the under-hood fusebox to reset the codes (and make your bizarre idling go away for a few days).

I think that only works for OBD-I (pre 1996), not OBD-II. Some OBD-II codes disapear on their own after several fault-free cycles, other more serious codes are required by law to remain intact so that the car owner is forced to seek an expert in pollution control.



Do you know what kind of fuel trims your ECU is spitting out?? Long-term FT should be -10% to +10%.

I remember my fuel trim recordings being within the normal range. And as I have been getting a year round mileage above 31 miles per US gallon, I have never had reason to believe that I was running overly rich or overly lean, thus my O2 sensor has been working well and since the recorded calculated fuel trims are in spec, then I have not had reason to suspect any unmetered sources of air or fuel.


Have you tried cleaning the TB out good with some carb cleaner? How about removing the PCV valve and cleaning it with some carb cleaner and verifying that it is indeed still good (or just replacing it altogether) - if the PCV valve gets crudded up, it'll remain open and allow too much recirculation (rich mixture).

One forum member reported having had his TB cleaned in the region of his IAC valve. He claimed that the problem went away. I will try to contact him to see if this resolution has been permanent. The reason that I was always suspicious of his claim is that my pulsing problem started when my car was brand new and the TB passages should have been clean at that time due to the car having come from the factory, with little time for dirt to accumulate.


To check for vacuum leaks, get a propane torch and just open it up (without lighting it of course) and try aiming it around the intake manifold gasket and throttle body gasket or around the MAF sensor to see if the idle changes.

I might try that if the hose pinching fails to produce results. I would only aim the propane at any point downstream of the MAF sensor, so that the MAF sensor continues to generate the same readings.


It could very easily be something within the programming of the ECU, but it could also be a problem that's only there during cold operation (stuff contracts when it cools down and could easily create a leak somewhere that fixes itself once warm a little bit). If you have the chance to get back to a scanner, I would really focus on the MAF sensor readings - scrap the O2 sensor readings, as they are no good for at least a few minutes of operation until it heats up.

Given that the pulsing starts and stops at about the same point in the startup cycle from day to day, I am led to believe that the suspected air leak is there year round but it is only when the ECU must make calculations for a cold weather startup situation that there is this side effect (pulsing) caused by the leak.


I'd agree that it is most likely in the ECU programming that's causing this, but it couldn't hurt to fiddle around with it a bit - you might find something more.

I have been reluctant to put on my mechanics cap given the fact that according to these forums, many profesional mechanics across the continent have all thrown their time and patience at this problem without success. I know that sounds like I am making excuses, but I don't have the heart to face yet another disappointment should the hose pinching demonstrate nothing new. Perhaps when I get back from my winter vacation at the end of this month will I find the courage to open the hood one more time in the cold.

Thank you much for your generous replies.

"I think that only works for OBD-I (pre 1996), not OBD-II. Some OBD-II codes disapear on their own after several fault-free cycles, other more serious codes are required by law to remain intact so that the car owner is forced to seek an expert in pollution control."

Nope - pulling the EFI 15A fuse resets the keep-alive memory. This erases ALL learned fuel trims and all fault codes, be it OBD-I or II. Many times, if there is a code, the CEL will remain on for several drive cycles if the fault does not re-appear, but the code is still stored in memory (whether the CEL is on or off). Pulling the fuse or disconnecting the battery will "re-boot" the ECU.

Trav

Nope - pulling the EFI 15A fuse resets the keep-alive memory. This erases ALL learned fuel trims and all fault codes, be it OBD-I or II. Many times, if there is a code, the CEL will remain on for several drive cycles if the fault does not re-appear, but the code is still stored in memory (whether the CEL is on or off). Pulling the fuse or disconnecting the battery will "re-boot" the ECU.

Trav


My wife's 98 Sentra (with OBD-II) had the CEL light come on after the O2 sensor failed. In spite of my replacement of the O2 sensor, we had to pay the dealer to reset the CEL light.
Had her car been OBD-I, it would have been easy to reset the CEL by pulling the ECU fuse.

Please confirm to me that the 2003 and recent Corolla with OBD-II is different from the Sentras and other cars which require a scanner to reset the cel light.

Also, is there non-volatile memory in the Corolla's ECU which may stores events even if the fuse has been pulled?

Thanks again.

OBD-I or II makes no difference...pulling the ECU fuse resets the ECU and clears ALL diagnostic data (including diagnostic trouble codes). Nissans are a little quirky in that the fuse must be left out for a LONG, LONG period of time (usually it takes a full 12 hrs at least to erase the codes - somtimes longer). Toyotas - as long as the fuse is removed for at least 1 minute, you should be fine.

If you do NOT pull the ECU fuse, then you will need a code scanner to reset the CEL. The only advantage to using a code scanner to erase codes is that it doesn't erase the fuel trims and non-continuous tests.

The non-volatile memory stores only the default fuel maps and ignition timing maps (and I'm sure a few other things). However, fault codes, fuel trims, all the diagnostic info it gathers, is volatile memory. There's nothing stored in the ECU non-volatile memory about running conditions at all. Pulling the ECU fuse will leave it in the state it came off the assembly line.

Trav

Pulling the ECU fuse will leave it in the state it came off the assembly line.Trav

That is good information for me to know.

I'll try these tests as soon as I can.

Thanks

OK, If I understand you, you are saying that after you reset the cpu, the car will cold idle at a reasonable steady rpm (say between 1400 and 2000) but after a few days, the cold idle becomes lower and the smoothness disappears because the idle is too low?



If true, we may be suffering in the same way.



oops forgot about this thread..

Yes after resetting the cpu, it will idle steadily for 2 maybe 3 days .. then go back .. I'm not entirely sure if it is the same problem, cause it was just a recent problem, but I've been trouble shooting this problem for a while and only fixes when I either pull the ecu fuse, or disconnect the battery.

Hello again, it's been nearly 8 months since I updated this thread.

Normally I would not want to bump it up to the front page until at least November, the month when the weather becomes cold enough to allow old and new members to be reminded that this problem is still there.

In late June 2005, I received a committment in writing from the head office of Toyota Canada that they would be "investigating this issue when the cold weather resumes".
Well the cold weather of winter 2005/2006 came and went without any news from headoffice.
By late summer 2006, I was becoming impatient and I contemplated creating a followup letter to Toyota headoffice asking for some concrete proof that some effort was going into this investigation.

I sent a letter to an automobile journalist who writes a weekly column in my local paper. I asked him what questions I should be asking Toyota under the circumstances. He didn't even bother to respond so our issue is either a taboo subject or too frivilous for his consideration.

Fortunately, a letter sent last month to the Automobile Protection Association (of Canada) fell on much more sympathetic ears, those of president George Iny.
George Iny co-hosts a call in radio show each week on a local AM radio station. He has invited me to call in, perhaps even be a guest.

I am preparing for this eventuallity and I am hopeful of getting the audio recording played on the air.

I even tried to sneak an e-mail about the pending radio program to the president of Toyota Canada, via the JAMA web site, of which he is also president. My e-mail was read at JAMA, but never an acknowledgement of it having been forwarded.

The reason I am setting up this post is that I want to formalize the fact that 4 of us voted YES in the poll attached to this thread.

While the poll is anonymous, there are posts in this thread made by 5 owners claiming to have the identical issue. Apparently, not everyone voted in the poll located in the first post. Please do so now.

They are as follows in no particular order:

John2000ve '00 location:Texas
CorollaULEV '03 location: Virginia
AUDI '03 location:Ontario
rated_w '?? location :Ontario
Montreal '03 (Matrix)location:Quebec

Do any of the listed owners want to add any comments about what has happened to their cars in the last 12 months?

Did any of you have additional work done above what you already mentioned in your posts in an attempt to correct this issue?

Nicknames are nice, but do you think that it would be a good idea for me to build a list of real names of the affected owners so that I can forward this list to the APA. If so, PM me and I'll send you my personal e-mail address.

Thanks

my cars makes this noise when it breaks

my cars makes this noise when it brakes

For you to have the exact same problem that the rest of us 20 are having, you would have to be hearing this noise when you press the clutch in or place the manual transmission in neutral in anticipation of coming to a full stop, or in anticipation of changing gears.

Is this your case?

Does this noise happen more than once a day?

If only once, is it always and only within 2 minutes of starting your car?

Does it happen only in winter when very cold?

Have you ever started your car when cold and left it in neutral while watching your stopwatch to see if it happens in the second minute?

What year and model is your car?

Have you tried to have it attended to under warranty?

Knowing the answers will help us evaluate your application for membership to our very exclusive club.

Hi everyone,

I have a new report of a Corolla owner and a Vibe owner chiming in on the other forums about having the same problem. We are 23 owners now.

My car has just come out of summer hibernation and is hunting again.

Any new Corolla owners here have anything unusual to report?

Thanks

I AM PLEASED TO ANNOUNCE THAT TOYOTA CANADA TELEPHONED ME TODAY TO ADVISE THAT WHAT THEY CALL A "REPAIR SOLUTION" IS PENDING AND THEY HOPE TO DELIVER IT TO ME BEFORE THE END OF THE YEAR.

My dealership has already been advised to expect a communication.

This will NOT be a technical service bulletin.

I pointed out on the telephone that there have been many attempts to fix this idle hunting by the now 23 car owners with this problem, and that all approaches have failed to date.

Toyota's answer is that they have made a serious effort in formulating the new proposed "repair solution" and I should have a reason to trust that it will succeed where traditional approaches by many shop mechanics have failed.

Stay tuned...

16K miles and no problems here. Going through second cold spell now (Thanks to the Canadians LOL) and it's supposed to get down to single digit temps (F) tonight.

At about what temp. does this problem start to occur? Just curious...

At about what temp. does this problem start to occur? Just curious...

It takes several days of sub 32 degree F weather for the computer to adjust and it also takes about the same time when the weather gets warmer for the computer to unadjust.

If it is going to happen to you, your engine would have, in my opinion, at least 2 things wrong with it, as the computer can usually arbitrate a conflict in data coming from several sensors, when there is only one thing wrong with your engine.

If it happens to you, you can pull the computer's fuse (EFI 15 amps) and see if the problem goes away for 2 days.

It has happened to so few of us (23) that I doubt that it will happen to you if it didn't already happen when your car was new.

It's been below 32 F for about a week or so and no trouble, so I guess I am in the majority with a normal running engine.

Hope you get a cure soon.

1) It's annoying

2) I believe it would hurt your resale value, I wouldn't buy a car if it had a problem like your car has. Sorry to be blunt like that, but recently declined buying a car for my son and one of the reasons was because it did the same thing you car is doing.

Not for the same reason, I think it was a vacuume leak and your problem is obviously not a vacuume leak.

It's been below 32 F for about a week or so and no trouble, so I guess I am in the majority with a normal running engine.....
..... I think (my son's prospective car problem) was a vacuum leak and your problem is obviously not a vacuum leak.

Glad to learn that you don't have this problem. I would not wish it on anyone.

The reason that an unmetered vacuum leak has often been proposed as the root cause is that it is easy to imagine a senario developing from a vacuum leak which has idle hunting as the end symptom.

1)The air leaks in downstream of the air flow sensor so the computer has no idea there is a leak.
2) The air leak leans the mixture.
3) The computer detects the lean mixture combustion byproducts thanks to the oxygen sensor.
4) The computer orders a permenant richness to compensate.
5) When starting in cold weather, this extra richness is more than necessary and the idle rpms exceed 2300.
6) The computer sees 2300 rpm without the foot on the gas pedal and does not know if the car is standing still or coasting down a hill, so it switches on the usual deacceleration fuel cut to create compression.
7) The rpms fall low enough for the fuel to be resumed.
8) The rpms climb again past 2300.
9) Steps 6,7, and 8 repeat until the oxygen sensor is warm enough to report that the mixture is too rich and should be leaned out. The coolant temperature also has risen enough for the fuel to be reduced.
10) The idle hunting stops for the rest of the day.

You see how easy it is to start with a vacuum leak and build it into an easy explanation for what causes idle hunting.

UPDATE:
Toyota Canada advised me today that the fix will not be arriving before the end of 2006, but in early 2007.

The good news is that it will be delivered in the form of a software (firmware) update to the ECU.

This would indicate that Toyota has done some serious research into the cause and solution.

It is unknown at this time if there will be a TSB associated with this fix.

Toyota Canada says that this fix will be made available if necessary to other Canadian Toyota owners who might require it to solve an identical problem in their cars.

Unless there are different rules (EPA?) that apply in the United States, I personally hope that if this fix works in Canada, it will be quickly offered in the States as well.

HI everyone,

I just purchased a 2003 Corolla 5 spd two weeks ago, and I am experiencing the very same problem. When cold starting at below 0. Engine RPM Pulses between 2000 and 2300 roughly during the second minute (I'm yet to time it with a stop watch).

It looks like i'm another unlucky one.

It looks like i'm another unlucky one.

You have become member number 35 of our exclusive club. I have little doubt that the party who sold you your car was aware of this problem but failed to disclose.

The re-calibration software update has been promised by Toyota Canada for early 2007.

I suspect they are delaying its release because they want to reassure themselves that their fix really works in real world conditions, and that requires an uninterrupted stretch of cold weather to allow the secret formula to be fine tuned. That's my generous take on the delay.

I'll PM you as soon as a working solution is delivered to the field.

Many low mileage cars of the same model year as yours will soon be coming off their 5 year warranty. I suggest that you notify your dealer in writing saying that you will require the fix to be installed free of charge, even if it is eventually delivered after your car's 5 years are up.

Thanks for posting.

Thank you Montreal. I will contact the dealership this weekend and make sure they will fix it free of charge. I purchased the car from a Toyota dealer (off-lease). Recently it has been rather warm so it would not surprise me if the dealer did not notice the problem. The car has only power-tran warranty left, which may not cover the fix, but since i just bought the car, I have a 30 day bumper to bumper warranty. I hope they wont just tell me that there is nothing wrong.

By the way this morning I started the car at -5 C. It started making the sound at about 80 seconds after start and ended at roughly 120 seconds. My car does not rev up and down as fast as in the audio clip, it's about 5 or 6 seconds per cycle (not as annoying). So it only does it about 7 or 8 times per start.

Cheers, Andrew

....... The car has only power-tran warranty left, which may not cover the fix, but since i just bought the car, I have a 30 day bumper to bumper warranty. I hope they wont just tell me that there is nothing wrong.

By the way this morning I started the car at -5 C. It started making the sound at about 80 seconds after start and ended at roughly 120 seconds. My car does not rev up and down as fast as in the audio clip, it's about 5 or 6 seconds per cycle (not as annoying). So it only does it about 7 or 8 times per start.

The engine computer should be part of the 5 year powertrain warranty, and since it also plays a key role in controlling pollution, it may be argueable that it should fall under the 8 year pollution control component warranty.

As for the number of "pulses" and the delay between each one, that is variable with the temperature and viscosity of the engine oil. This varies throughout the winter and it is not unusal to find that as the outdoor temperature gets colder, there are more pulses occurring and they are spaced more seconds apart.

As weather turns colder and then warmer, it takes several days for the computer's adaptation processs to fully take place, so symptoms may be newly appearing and disappearing when least expected.

The key to stopping this is to get the peak rpm to never go above the nominal range of 1800 to 2000, and that can only be achieved through the re-calibration software.

Now for the news we all have been patiently waiting for since 2 years.

The long awaited software patch was installed on my car last friday morning, February 9, 2007.

It works. Yes, Toyota fully understood the problem and came up with an authentic solution.

The installation of any software version in my car was the equivalent of doing an ECU reset in that with or without this patch, my car would be expected to immediately operate properly, and it did. It would take several days for me to begin to sense any durable improvement.
Following the installation, I left the city for a weekend trip to ski country, a hundred miles north of Montreal.

The car spent its first night with a low of about minus 14 F, colder than I can ever recall in the last 5 years. The next morning the car started and the peak idle never went above 2300 with no pulsing at any time. The rate at which the rpms dropped progressively over the next 3 minutes was quite impressive. Later that day, I started the car for the second time, and the results were similar.

The car spent the second night with a low of about minus 15 F. The next morning, the motor raced above 2500 within 10 seconds, followed by 4 pulses, after which, the engine quickly slowed down progressively without any pulses.

I am going to suggest that the 2500 rpms peak was triggered by the excessively cold overnight temperature and by the fact that the ECU had not completed it adaptation process which usually takes several days. It would appear that where the safety limit used to be 2300 rpm before the motor would be temperarily cut, it has now been revised upwards by 200 rpm to 2500. The car was restarted one more time that same afternoon without the peak rpms hitting 2500, and with no pulsing. I then brought the car back to the city last sunday night.

The coldest it has been this week where I live is minus 9.5 degrees F. , this being relatively warmer than the minus 15 degrees of last weekend.
The car has stayed outdoors and been started at least twice each day for the last four days. At no time has there been any pulsing.

I conclude that the ECU recalibration has solved the problem.
At this point in time, there are at least 19 other car owners in Canada (14 Toyota/5 Pontiac) and at least 17 other car owners in the United States (13 Toyota/4 Pontiac) which share this problem.

Most of you are anxiously awaiting news about how to obtain the same fix.
I have received so far mixed messages directly and indirectly from Toyota Canada as to whether or not a technical service bulletin will be eventually published. Publishing is expected to add several months to any rollout.

I have no doubt that you would like to receive your ECU update while it is still cold enough for your cars to demonstrate that the fix is indeed working rather than being obliged to wait until next autumn.

I hope you will approach your dealerships being respectful of the fact that a little patience with Toyota and Pontiac will be necessary, as they are still in the preliminary stage.

Now you know.

I have updated the beginning of the first post of this thread to draw attention to the official release by Toyota of bulletin TSB2754, designed to solve this problem.

i usually just slam on the gas a little then it goes away!

Oh my god, I just found this posting and my 03 Corolla does the EXACT SAME THING! I have no idea what to do or where to go, can anyone help? I'm going to call the 800 number and I'll take the poll. I can't thank you enough for publishing all that info!

Is anyone still viewing this thread? I hope so...I was wondering if this ECU software patch was still available?

I've had Toyota do the "ECU recalibration" for me this winter. They did not really care for the TSB number. I just told them whats wrong and they decided that the recalibration should be done. The fix is good. The car seems to idle a little lower now and never reaches 2300 RPM (with the rare few exceptions). Since the fix the RPM has gone over 2300 and cut off just a few times, and never more than once in a row.

Make sure you get it done before 130,000KM so you don't have to pay.

Thnanks for all the info Montreal !!

I have an '04 rolla 5 spd and it can be between 40F and 50F and it will get up to 2300 and cut out once, maybe twice and gets worse the lower the outside temp is. I will probably now have to wait until fall and cooler temps b4 I take this in for the ECU flash.

Wow, I wish I had found this forum sooner.....got 160K on my '03 Corolla so I'm sure they'll want me to pay for it. But it sure is an annoying sound so I'll be getting this taken care of closer to wintertime. Thanks for all the hard work in finding a resolution with Toyota!
:clap:

Is anyone still viewing this thread? I hope so...I was wondering if this ECU software patch was still available?
I'll put my hat in now as a new member to the Toyota rev hunting problem. I have a 2007 Corolla manual tranny. At approx. 45,000km the car started to hunt revs when cold. If the temp is +4 C or less and the car has sat overnight the engine starts and idles fine and after 1.5 km of driving if I unload the tranny and coast to the stop sign the engine starts hunting revs between 1,300 to 2,300 rpm every 1.5 seconds or so. It's worse the colder it gets. The car will do this at idle as well only in -15C after overnight cold soaking. Starts fine, problem starts after 1.5 km....and if cold enough I can get out of car and walk around as it hunts. If temp is any warmer the car only will do it when the engine is unloaded and rolling to a stop sign but usually stops when the vehicle stops. In all cases the problem is an every time problem...it always does it if below -4....it isn't intemittent...then it always goes away after vehicle travels about 4 or 5 km.
Dealer has replaced many sensors, the throttle body, the CPU. Nothing changes. The dealer said that maybe that is what that car is supposed to do?? "the nature of the beast" I can recall him saying!!!! As I sit beside my $24,000 out the door cost of my Toyota I can't imagine that I would have touched this car sounding like it does. I gave them the TSB number you gave and they said that was an old one an would have been fixed by 2007 vehicles so it didn't apply. Does anyone have a newer model Corolla doing this. Any help or any specific words to get them to fix this? This is not the "nature of the beast" I'm sure.