Myth or Fact? Gen-4 Sludge problems?

[inuhbad]

I'm curious - I drive a 97 V6 Camry, and I love it!

Aside from the occasional little maintenance item, I've not had many problems until just recently (bearings, hubs, and lower ball joints need replacing)! Every time I tell my friends how much I love my Camry, and how reliable it has been - they always tell me, "Yeah, but I heard those gum up with all sorts of SLUDGE problems!"

Honestly, I've not had ONE single problem that was sludge-related! I change my oil every 3000-5000 miles with Valvoline MaxLife Synthetic, I use a Mobile 1 Oil Filter, and run cleaner additives every ~5 or 6 tanks of gas. I've not had one single problem with any sort of 'sludge' at all!

Is this really a problem, or is this (as I suspect) just a problem with cars where people routinely go over 5000+ miles without any oil changes, or they forget to change the oil now & then?

I've also been blessed with an engine that doesn't seem to have any problems with leaking or burning oil either!

I used to take my car to Valvoline Instant Oil Change, and after they screwed up two of my cars in the past, I've learned my lesson - the only way to ensure your car is cared for PROPERLY is to DIY, and follow periodic maintenance & parts replacement intervals as best you can, and using quality parts & materials.

Even though I've heard a lot about 'Sludge' in this V6 Gen4 engine, I've never seen it, and I think it's quite possibly one of the most reliable of Toyota Engines ever built!

[ninja92]

I got the 4 cyl. 97 camry, and it was my dads daily beater of 80 miles a day, currently 205K, and it runs great. Using Mobil 5w-30 full syn. and he changed the oil and filter every 5K miles. I'm gonna change it every 4K, because of stop and go city traffic. I'm more worried about the tranny than the engine lol.

Grandpa's 94 Corolla runs like new. He uses non synthetic and changes out the oil every 3K miles or 6 months.

Toyota cars and engines are amazing if you take car of them, imho, but then again most japanese cars are really good quality.

I'm a sucker for 90's era japanese cars lol

NSX....

[sc2dave]

Don't forget to also change the transaxle fluid.Do a search to see if yours has a seperate sump for this or not.

[hill8570]

The 1MZ from roughly 1996-2002 (too lazy to go back and look up when the redesign occurred, sorry) was not very tolerant of extended change intervals with dino oil, especially for cars that did a lot of short trips (read: lots of moisture buildup in the oil). Didn't help that Toyota recommended something like 7500 mile change interval in the owner's manual -- that leaves pretty much no margin if someone waits a "bit" after 7500 miles.

3000-ish OCI on dino, or just run synth and you're unlikely to sludge.

[Michael503]

Originally Posted by inuhbad

I'm curious - I drive a 97 V6 Camry, and I love it!

----
Even though I've heard a lot about 'Sludge' in this V6 Gen4 engine, I've never seen it, and I think it's quite possibly one of the most reliable of Toyota Engines ever built!

The ugly truth is, yes, they can make sludge... and lots of it. The problem is mainly caused by poor crankcase scavenging, but there may be other factors. An improvement would be a redesigned valve cover and some method of purging the gases from the lower crankcase, but that would require Toyota to re-certify all the cars for emissions... and that ain't gonna happen.

There are basically 2 ways to prevent this, change your oil frequently or get the oil hot every time you drive it. Synth helps a lot too.

The sludge is produced when the oil becomes saturated with contaminants and then begins to condense and coagulate on cooler surfaces. This is aggravated in damper climates. Any vehicle will make it under the right conditions, this one is just better at it.

There are some horror pics on the net of someone disassembling and vatting a V6 that has 8000 miles on it and is totally sludged. These 8000 miles did not occur over just a 3 month period and most likely occurred when the owner drove very short distances for a very long period of time. I doubt the oil ever got hot.

You would be surprised at how long you can go between oil changes and how clean the crankcase will stay if all you do is drive the on interstate for long distances. I doubt long haul truckers stop every 3000 miles to change the oil.

My personal experience with a gen3 4 cylinder is that normal town driving, with long OC intervals and possibly a failed thermostat will produce sufficient sludge to clog the oil strainer. I have maintained this car for 12 years and have fought a constant battle with sludge due the the drivers route to work and my unwillingness to change the oil every 2 months.
I have owned a variety of vehicles since 1977 and have never had one that made sludge like this. I keep a spare PCV valve in a jar of lacquer thinner jus to swap out when the other one clogs, which is usually about every 9-12 months. Once it clogs, the engine scavenges less, and more sludge is born.

I became a Toyota man back in 79 and have raved about them over the years, but after having owned this engine, and reading about the unintended acceleration that they're in denial about on the rest of the fleet, ... we're done. I don't know what I'll get, and it may not be better, but I'm sure gonna research it before I get one.

[camry6]

Originally Posted by Michael503

The ugly truth is, yes, they can make sludge... and lots of it. The problem is mainly caused by poor crankcase scavenging, but there may be other factors. An improvement would be a redesigned valve cover and some method of purging the gases from the lower crankcase, but that would require Toyota to re-certify all the cars for emissions... and that ain't gonna happen.

There are basically 2 ways to prevent this, change your oil frequently or get the oil hot every time you drive it. Synth helps a lot too.

The sludge is produced when the oil becomes saturated with contaminants and then begins to condense and coagulate on cooler surfaces. This is aggravated in damper climates. Any vehicle will make it under the right conditions, this one is just better at it.

There are some horror pics on the net of someone disassembling and vatting a V6 that has 8000 miles on it and is totally sludged. These 8000 miles did not occur over just a 3 month period and most likely occurred when the owner drove very short distances for a very long period of time. I doubt the oil ever got hot.

You would be surprised at how long you can go between oil changes and how clean the crankcase will stay if all you do is drive the on interstate for long distances. I doubt long haul truckers stop every 3000 miles to change the oil.

My personal experience with a gen3 4 cylinder is that normal town driving, with long OC intervals and possibly a failed thermostat will produce sufficient sludge to clog the oil strainer. I have maintained this car for 12 years and have fought a constant battle with sludge due the the drivers route to work and my unwillingness to change the oil every 2 months.
I have owned a variety of vehicles since 1977 and have never had one that made sludge like this. I keep a spare PCV valve in a jar of lacquer thinner jus to swap out when the other one clogs, which is usually about every 9-12 months. Once it clogs, the engine scavenges less, and more sludge is born.

I became a Toyota man back in 79 and have raved about them over the years, but after having owned this engine, and reading about the unintended acceleration that they're in denial about on the rest of the fleet, ... we're done. I don't know what I'll get, and it may not be better, but I'm sure gonna research it before I get one.

There is a redesigned valve cover for the rear bank of the 1MZ-FE engine. It is available through TOYOTA. It is designed to provide better flow for removing crankcase gasses. I installed one on my friends 2001 Highlander. The cover cost around $250.00 canadian,...... so that's probably like $50.00 US...haha.

[93celicaconv]

Wow, I just learned something from Michael503. I thought engines create sludge from running hot and burn off the liquids to create the solids. You said engines sludge from never running hot enough.

I bought a 93 Celica convertible with only 100,000 miles a year ago (5S-FE engine). The thermostat was stuck open when I bought it, so the coolant never got to normal operating temperature, especially when driving on the highway. I changed the thermostat and the PCV soon after I got it home (the one in the valve cover was no longer functioning).

After seeing the valve cover leaking some oil, I decided to change the valve cover gasket. Oh my! I never saw so much sludge on a 5S-FE, or any other engine. I talked to a mechanic, and he said the stuck open thermostat probably helped to not make the siutation worse. I broke off the larger pieces, but was afraid to get lots of small pieces headed for the oil pan. I cleaned the valve cover, then flushed the engine with a flushing chemical from NAPA. I am running a quart of Risolone in the oil in hopes to gradually clear some of this stuff, but I'm not sure if it is gettnig better or getting worse. I'm just not sure how to take positive steps to clear this stuff up. Do you have any suggestions?

[fenixus]

Originally Posted by 93celicaconv

Wow, I just learned something from Michael503. I thought engines create sludge from running hot and burn off the liquids to create the solids. You said engines sludge from never running hot enough.

I bought a 93 Celica convertible with only 100,000 miles a year ago (5S-FE engine). The thermostat was stuck open when I bought it, so the coolant never got to normal operating temperature, especially when driving on the highway. I changed the thermostat and the PCV soon after I got it home (the one in the valve cover was no longer functioning).

After seeing the valve cover leaking some oil, I decided to change the valve cover gasket. Oh my! I never saw so much sludge on a 5S-FE, or any other engine. I talked to a mechanic, and he said the stuck open thermostat probably helped to not make the siutation worse. I broke off the larger pieces, but was afraid to get lots of small pieces headed for the oil pan. I cleaned the valve cover, then flushed the engine with a flushing chemical from NAPA. I am running a quart of Risolone in the oil in hopes to gradually clear some of this stuff, but I'm not sure if it is gettnig better or getting worse. I'm just not sure how to take positive steps to clear this stuff up. Do you have any suggestions?

heh, wait for pics of my crankase after i open the valve cover next weekend or so. 5s-fe from 2000, prev owner said never changed oil in first 35k miles
i used to run it on local shop or Firestone's promo dino oil change and poor filters, only last summer switched it to synthetic, flushed coolant and replaced with fresh toyota red with water. replaced thermostat at same time when water pump and timing belt (all OEM) was done.
I sea foamed the car once, later by peeking through the oil fill hole i could see it got brighter a bit. more to come

[93celicaconv]

Exactly how did you "Sea Foam" your engine? As a flush for a 5-10 min. run, then changed the oil? Just before an oil change and ran it 30-60 min., then changed the oil? Or do you run Sea Foam in your oil all the time?

I think Sea Foam gets the varnish color out, but does it really remove solid, crusty sludge?

[fenixus]

i was at 5k mobil1 oil change interval, so i changed oil to fresh castrol gtx 5w-30 with purolator pureone filter (was @ $13.99 on promo in pep boys).
drove a car around for 30 mins maybe to get it warm.

then added 1/3 of can to tank (was 1/4 full), 1/3 to crankcase and sucked most of rest via brake booster port on engine (took me 2 times to get it done). left it for 5 mins, then revved the hell out of it (2,500-5,500rpm). there was LOTS of white fumes for few good minutes each time i did the last step (twice).
then took it to highway and liberally used L & 2 gears on ramp and then ran it with O/D off mostly for an hour (70 miles). fuel was low so tanked it up.

changed oil again to fresh Valvoline Synpower 5w-30 ($26.99 in autozone with Fram TG filter) with Denso oil filter this time.

[Michael503]

Originally Posted by 93celicaconv

Wow, I just learned something from Michael503. I thought engines create sludge from running hot and burn off the liquids to create the solids. You said engines sludge from never running hot enough.

I bought a 93 Celica convertible with only 100,000 miles a year ago (5S-FE engine). The thermostat was stuck open when I bought it, so the coolant never got to normal operating temperature, especially when driving on the highway. I changed the thermostat and the PCV soon after I got it home (the one in the valve cover was no longer functioning).

After seeing the valve cover leaking some oil, I decided to change the valve cover gasket. Oh my! I never saw so much sludge on a 5S-FE, or any other engine. I talked to a mechanic, and he said the stuck open thermostat probably helped to not make the siutation worse. I broke off the larger pieces, but was afraid to get lots of small pieces headed for the oil pan. I cleaned the valve cover, then flushed the engine with a flushing chemical from NAPA. I am running a quart of Risolone in the oil in hopes to gradually clear some of this stuff, but I'm not sure if it is gettnig better or getting worse. I'm just not sure how to take positive steps to clear this stuff up. Do you have any suggestions?

There are numerous posts on desludging under the VC(s), one of the best ones suggests a shop vac combined with selective picking. There are however, deposits that form elsewhere, such as on the balancer assy in the crankcase (5SFE). These will dislodge and end up in the strainer if you run a solvent through the engine. They may not do it right away, they may do it a year from now, but they will come loose. The problem with aggresive solvent treatments (kerosene, deisel fuel, High doses of ATF, engine flush, etc) is that they break the small stuff free at flush, but soften the larger deposits and they break free later, say when you finaly get the thing hot for long time. There once was an engine flush that I can no longer find, but was basically toluene, acetone, etc (lacquer thinner), that had a disclaimer on the can that essentially said, if your engine was actually dirty, you would need to drop the pan and clean the strainer or serious engine damage could result. Solvents and cleaners should be used with extreme caution.


What usually happens with engine cleaners is they soften the deposits, which then break free and end up in the oil strainer at a later date, usually after you've forgotten about them. The only clue you get is the oil light comes on. This requires dropping the pan, assuming you didn't toast the engine from oil starvation.

After I had to do this to mine, I came up with another method for strainer cleaning, but its still a bit time consuming and you don't actually get to see the strainer and it costs more. I did some experiments with engine deposits and found that they're composed of basically 2 things in laymans terms, soft soluble stuff and hard crunchy stuff, glued together by the soft stuff. With the soft stuff dissolved, the hard stuff is no bigger than sand and can pass through a strainer easily. When the globs break free. its the soft stuff that glues them to the strainer mesh.



My method for cleaning the screen is this:

The idea is to dissolve the soft stuff in the strainer without breaking any more free elsewhere, thus worsening the problem. Do not attempt this with a warm/hot engine.


1: drain the oil and let the engine cool. remove the oil fill cap (for vapor venting)

2: reinstall the drain plug and pour a pint of high strength solvent, like lacquer thinner down the dipstick tube and let it sit, several hours, but preferably overnight. Do NOT pour into the oil fill hole!
If you wanted to accelerate the process, you could get a device that vibrates, like an aquarium pump, glue it to a big magnet and stick it to the bottom of the pan. This will dissolve the goo holding the small hard chunks together and into the strainer mesh. You should note that the inside of the camry oil pan is painted, and chemicals that strip paint will strip the inside of the pan, so don't use too aggressive a solvent, (don't use paint stripper)

3: drain thoroughly (into a clean pan, if you want to see the result) If on the outside chance you see large strips of black paint, drop the pan.

4: reinstall the plug and add a pint to a quart of mineral spirits down the dipstick tube, allow it to sit for a few minutes and drain it as well. Do NOT pour into the oil fill hole

5: add 1 quart of oil (oil fill hole), let it sit, and drain. This should get rid of most of the solvents

6: refill with oil and run the engine for just a few minutes, and change the filter. run it again, around for a few minutes and change it again.

The strainer should now be clear enough to pass oil. Keep an eye on the oil and change it if it shows signs of getting dirty earlier than usual.

[inuhbad]

Wow... You guys seem to be having all sorts of problems!

My daily commute is 23 miles past two downtown areas (Twin Cities), where I'm going 65 MPH for part of the way, and then through stop & go bumper-to-bumper traffic! My 23 mile commute regularly takes over 1 hour each way!

Even in sub-zero -15 degree F weather, my engine is ALWAYS getting up to full temperature on my daily commutes! I've always used Synthetic Oil on the car since I bought it in 2006, and although I noticed some 'goo' just inside the oil fill cap area when I bought it - I've seen it disappeared quickly as I drove the car more & more.

So far I've had about 75,000 trouble-free miles on my car.

I've never heard of the acceleration problems on the Gen4 and earlier Camry... I saw that the NTSB is looking into a crash with a 1996 Camry that purportedly killed someone. A man seemingly deliberately killed another person by running them down, and when asked if his car accelerated without him touching the gas pedal, he replied, "NO." And yet the NTSB is continuing the witch-hunt, and now looking into earlier model Toyotas.

Never saw this kind of a crazy witch-hunt when the Ford Pintos first started exploding, but now that the Government is in the auto industry it kind of makes you wonder.

My car has never had unintentional acceleration. I also thank God that I've never had a problem with this Sludge issue either. I guess my commute is just about right for the car.

[Nervous]

Originally Posted by fenixus

i was at 5k mobil1 oil change interval, so i changed oil to fresh castrol gtx 5w-30 with purolator pureone filter (was @ $13.99 on promo in pep boys).
drove a car around for 30 mins maybe to get it warm.

then added 1/3 of can to tank (was 1/4 full), 1/3 to crankcase and sucked most of rest via brake booster port on engine (took me 2 times to get it done). left it for 5 mins, then revved the hell out of it (2,500-5,500rpm). there was LOTS of white fumes for few good minutes each time i did the last step (twice).
then took it to highway and liberally used L & 2 gears on ramp and then ran it with O/D off mostly for an hour (70 miles). fuel was low so tanked it up.

changed oil again to fresh Valvoline Synpower 5w-30 ($26.99 in autozone with Fram TG filter) with Denso oil filter this time.

So? How do you know this procedure did something useful to your engine and not opposite?

[93celicaconv]

Yes, that is my question exactly. I know I had a lot of sludge buildup in my engine when I bought it, but just now discovered. I chipped away a lot of it from on top of the head. But there is still some there, and I am sure elsewhere in the engine. I think it is a good idea to try to remove it all, but I do not want to create worse problems by trying to clean up every last bit of sludge. So, what should a person do? Leave well enough alone, or run all these chemicals through? Which will have a more positive effect, and which may cause a more detrimental effect?

[zythr]

Best to try to get as much sludge out as you can. Areas of the engine that have sludge are either getting reduced lubrication or none at all, since the sludge can act like a "dam" blocking the oil from circulating.