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Camry / 2WD Pickup
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Discussion Starter · #1 · (Edited)
Hello all,


Please check my signature block for specifics on my Camry.

The problem started suddenly when the car had 62K miles on it. It had been sitting in the garage for a week when my wife tried to start it. She said it would not start for a while, it would just crank. When it finally started, she said it backfired pretty bad and the engine started making a loud knocking noise as it idled. She shut it down immediately. I suspect she was depressing the accelerator pedal when she was trying to start it. Even though she has not driven a car with a carburetor for many years, she still seems to have a hard time keeping her right foot on the floor when starting a car with fuel injection. Makes me crazy!

Anyway, I started the car up that evening and noticed a knocking noise that had never been there before. Since I had checked the valve clearances just a few thousand miles before this event, I pulled off the valve cover and looked everything over.....everything was fine.

The next thing I tried was a few bottles of Techron. No help.

The next thing I tried was a check of the EGR valve. Everything checked out fine.

I next tried to steth the engine. I don't have a real good mechanic's ear, but the noise definitely seemed to be coming from the top end. I stethed the oil pan and the lower part of the engine block and couldn't hear the knock much at all at these places.

The next thing I did was to buy a new knock sensor (mucho $$) and put that in. No help.

The next thing I did was to take it into a Toyota dealer. They did some load tests by pulling spark plug caps off one-by-one and said it did not seem to be a rod knock. They then ran some top end cleaner through it. Cost me $100 and did not help.

I then sucked lots of Sea Foam thru the engine via the brake booster hose. I even stuffed a Sea Foam soaked rope into a few of the cylinders and let it set there for a few days to dissolve any deposits. No help.

The next thing I tried was to pull off the exhaust manifold, check it out for cracks and such, and reinstall it using a new gasket. No help.

The next thing I tried was a tank of premium gas. No help.

The next thing I tried was a new timing belt and new pulleys. No help.

The next thing I tried was to send out this post and plea for help.

I'm bummin'. You can hear the noise when you start the car. It is a metallic sounding knock, sounds like it is somewhere in the top end. My Dad is a pretty experienced mechanic and says it sounds like piston slap. I can't imagine that this is what it could be. Remember, the engine started making this noise suddenly, after the big backfire (see above). The noise can be heard from the street as my wife drives the car away. I've noticed that when I'm driving it, the noise seems to go away above 3000 RPM and is most pronounced at low RPMs, especially during acceleration and going up hills. It gets a little quieter when the engine is warm, but not much.

I've changed the oil religiously every 3000 miles in this car. When I pull off the valve cover, it is very clean with no hint of sludge.

I'm at wit's end. I'm thinking seriously of throwing my hand up in disgust, purchasing towing insurance, and runnin' 'er till she blows!

Any assistance would be greatly appreciated.
 

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Paseo
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5,859 Posts
You can pull the sparkplugs out and shine a light into the holes to look at the piston tops, see if there are any shiny spots. If so pull the timing belt covers and see if the marks are still in alignment. While putting a belt on a 98 Camry I discovered turning the crankshaft backwards will allow the timing belt tensioner to loosen just enough to slip a cog or 2. The 5SFE isn't supposed to be an interferance engine however built up carbon could touch the valves. It's possible the backfire made the crank jump backwards.
My mom has the same problem with hitting the gas on f/i vehicles. She's even called me at work to come fix her car. Once I get there I tell her to show me what it's doing. Then have to remind her yet again to take her foot off the accellerator. But hey, it's mom, what am I gonna do, yell at her? Can't see that happening. heh
 

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Moving Forward
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3,144 Posts
You didnt mention the water pump being replaced. Sometimes when the bearings go out in it you will hear a knocking noise coming from it. FI you ahve a steth you can get to it right under the alternator. there is a water neck and it is in the same location as the pump. You may try listening to it. IF you replaced the t-belt and all the pulleys and suche it would be a pain if it was the pump since you awill ahve to remove the belt to get to it. COuld be psiton slap also. If you are pulling plug wires it may change the sound if it happens to be piston slap. IT would seem odd for it to be this though if it was fine before it was parked for the week.
 

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Banned
Camry / 2WD Pickup
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601 Posts
Discussion Starter · #4 ·
Tercel,

Thanks for the input. I'll pull the plugs and give the piston tops a look. I did just replace the timing belt. The valve timing was good when I started the job and good when I slapped the timing belt covers back on 'er.

Cyorke,

Yeah, I've thought of the water pump. I'll steth that area.

However, when I had the timing belt off of it, I grabbed the water pump pulley and tried to move it in all directions. It seemed solid.

Thanks for the inputs.....are there any more ideas out there?
 

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Banned
Camry / 2WD Pickup
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601 Posts
Discussion Starter · #5 ·
Dudes,

I stethed the waterpump area and I did not hear anything that seemed to indicate that the knock was coming from that area.

Regardless, the next time I change coolant in this car (about 10K miles from now), I think I'll throw a new waterpump on 'er and see if that clears up the noise.
 

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Moving Forward
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3,144 Posts
Digger1 said:
Dudes,

I stethed the waterpump area and I did not hear anything that seemed to indicate that the knock was coming from that area.

Regardless, the next time I change coolant in this car (about 10K miles from now), I think I'll throw a new waterpump on 'er and see if that clears up the noise.
You know this involves replacing the timing belt also. It is not like a SBC taht you jsut take the fan off the front and there you have a water pump. Just want to make sure you are aware so you arent surprised when you ahve to disassemble everything under the timing cover to get to it.
 

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Banned
Camry / 2WD Pickup
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601 Posts
Discussion Starter · #7 ·
Thanks, Chris,

As you can see from my first post in this thread, BTDT.

As a matter of fact, I've got less than 1000 miles on the new timing belt.

Since I've done the job so recently and I took good notes, getting in there to replace the waterpump SHOULD be a breeze (KOW)!
 

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Banned
Camry / 2WD Pickup
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601 Posts
Discussion Starter · #8 ·
Grrrr! New Waterpump - Still Knocks

I put a new waterpump (OEM) in and the noise is still there. (Plz see my post at the top of this thread.)

I just got back from a trip to Minnesota and noticed that it knocks really loud when the engine is really cold. She goes down the road good, though, I got over 34 mpg on the trip.

I'm considering getting an oil analysis done....know of any good labs? Will such an analysis tell me if the engine is beating itself to death? BTW, the engine is burning a quart of oil every 5300 miles. One would think that if I had piston slap that she'd be pushing a little more oil than that.

Also, is is possible for the head gasket to be leaking in such a way that no coolant or oil is leaking? I'm thinking of a situation where the head gasket may have a leak that merely allows combustion chamber gases to escape, causing a noise. Maybe the mighty backfire my wife caused blew a small hole in the head gasket.

Thoughts?

I'm pulling my hair out on this one!
 

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Banned
Camry / 2WD Pickup
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601 Posts
Discussion Starter · #9 ·
Update on my knock.....it is still there.

Just had an idea though. Does anyone think that the big backfire my wife caused could have bent a valve stem? Will a bent valve stem cause a knocking noise?

Thanks, all!
 

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1987 DX 5-speed
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21 Posts
It would probably worth while to get a cheapie oil pressure gauge from Walmart and see if you are getting good pressure. Your oil pressure light will not go on unless you are at super low pressure.
 

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Registered
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Hey buddy i kno what u mean....my family friend is a mechanice and we just got done unhooking the enitre damn engine.....i had the same knock nosie out of the blue one day and bout 3 days later it got louder and 3times faster........i tried to make it to the dealership and i made it but i wouldnt get any real power when i pressed the gas.....dealership said i needed a new engine and they qouted me $6350.....HELL NO!!!.....so got it towed home and now me and my friend are in the process of taking the head off....he tested my pressure int he cylinder i believe and they were all in the 120's expect the one that looks wet from oil which was 185......so to make a long story short.....brother get it looked at FAST....or you will be faced with what im goin thru....no ride for the 4th week now!!!!!.....o yea i got pics, i'll post
 

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15 Avalon Touring SE
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342 Posts
Does the engine still idle well? It sounds like you might have a broken exhaust valve spring, but that would probably cause a rough idle and a put-put sound in the exhaust. If that's not the case, then I'd drop the oil pan and check those rod bearings! One more thought, I've mistaken an exhaust manifold leak for a rod bearing noise on this style engine before. Take the exhaust shield off and make sure the nuts are tight.
 

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Banned
Camry / 2WD Pickup
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601 Posts
Discussion Starter · #14 ·
nitrous3sfe said:
It would probably worth while to get a cheapie oil pressure gauge from Walmart and see if you are getting good pressure. Your oil pressure light will not go on unless you are at super low pressure.
Nitrous,

Good idea, for peace of mind if nothing else.

Thanks!
 

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Banned
Camry / 2WD Pickup
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601 Posts
Discussion Starter · #15 ·
99sleeper said:
Hey buddy i kno what u mean....my family friend is a mechanice and we just got done unhooking the enitre damn engine.....i had the same knock nosie out of the blue one day and bout 3 days later it got louder and 3times faster........i tried to make it to the dealership and i made it but i wouldnt get any real power when i pressed the gas.....dealership said i needed a new engine and they qouted me $6350.....HELL NO!!!.....so got it towed home and now me and my friend are in the process of taking the head off....he tested my pressure int he cylinder i believe and they were all in the 120's expect the one that looks wet from oil which was 185......so to make a long story short.....brother get it looked at FAST....or you will be faced with what im goin thru....no ride for the 4th week now!!!!!.....o yea i got pics, i'll post
99,

I appreciate the info. However, my Camry has now gone 22K miles with the noise I detailed in the first post of this thread.

My Dad says I need to turn up the radio when I drive the car.
 

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Banned
Camry / 2WD Pickup
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601 Posts
Discussion Starter · #16 ·
DOHCammer said:
Does the engine still idle well? It sounds like you might have a broken exhaust valve spring, but that would probably cause a rough idle and a put-put sound in the exhaust. If that's not the case, then I'd drop the oil pan and check those rod bearings! One more thought, I've mistaken an exhaust manifold leak for a rod bearing noise on this style engine before. Take the exhaust shield off and make sure the nuts are tight.
Cammer,

Thanks for your thoughtful reply. The car idles well. In fact, it runs well. It just makes that #*&% noise.

I, too, suspected an exhaust manifold leak. As you can see from my first post in this thread, I've already taken off the exhaust manifold, inspected it for cracks, found none, and reinstalled it using a new gasket.

I might be suspecting a broken piston ring. Do I need to pull the engine the get one or more pistons out?
 

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Do 99 5SFEs have automatic valve lash adjustment or is it still shim adjust? If it's automatic, it could be a faulty lash adjuster since it seems to be coming from the top end and causing no real problems. If not, the camshaft bearing clearances or lifters may be out of spec and causing noise.

The knock and backfire was probably because she had the foot on the acc. pedal. It no doubt flooded the cylinders with the excessive cranking. Her foot on the accelerator pedal made the engine rev and push the excess unburnt gas into the exhaust manifold when it finally started; could that be a possibility? The low oil in the cylinder head didn't help any since its been sitting for a week, so it received accelerated wear at startup.

What kind of noise is it? Like typical knocking, slapping, ticking, or ?

A bent valve will no doubt cause problems, as will a burnt/sticking valve. A broken piston ring will no doubt cause noise, so steth the bottom end well. It should cause lower compression in one cylinder, so be sure to do a leakdown test. A compression test is useful, but a leakdown test will tell you exactly where a problem area is.
 

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If the car would have broken piston ring, the engine ill blow a lot of oil.
The exhaust manifold usually warps with use, causing bad exhaust leaks. Remove the exhaust shields, start the car when outside temp. is about 65 degrees F or below and watch for vapor puffs from the gasket area.
On one Camry the similar knock was caused by bad alt. front bearing damage called brinelling.
 

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MDT
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35 Posts
The knock is likely either a binding wrist pin (most likely with the evidence given) or the balance shafts have suddenly developed excessive clearance (a lot less likely, a lot!).

Balance shafts can sound just like a rod or carbon knock if the clearance is over .004". This would be highly unlikely with the evidence given - almost impossible actually)

The wrist pin binding will be loud when cold and get quieter as the engine warms. Pull the plug wires out one at a time while the engine is idling and knocking to see which cylinder is the noisy one. There will be no knock once the culprit cylinder is dead.

Because you are not having economy, running, or failure issues, I would not suspect a valve problem or a bearing issue. Knocking bearings aren't likely to go 22k.


Do not pull the oil pan yet to check the balance shafts. Let's do the free stuff first.
 

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The car I'm working on out of the blue developed a knocking noise. It sounded like a rod knock not deep enough for a main knock. What puzzled me was the knock would go away at about 2300 rpms and be more prevelant at lower rpms or idle. It did'nt make sense to me (but I'm not used to japanese cars just european). My curiosity got the best of me so I pulled the inspection plate on the tranny. I see the flex plate is rubbing against the block. OH OH bad thrust bearings or or washers or what ever toyota calls them. You may want to oake a look at that also it's easy enough to do. Good Luck
 
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