I first learned of the Toyota sludging problem when I came to this forum and the gear driven camshaft was labeled as the root cause. I didn't buy that at first (if you do a search of my posts on the subject at the time you'll see that), but some convincing arguments were made and I accepted it. BUT if it's true that these 3.4 engines have the gear driven cams, but NO HISTORY OF SLUDGING PROBLEMS, then it seems reasonable to me to conclude that the gear driven cams in the other two Toyota engines with sludge problems are NOT the root cause. They are probably a contributing factor, but something else is going on in those engines if the 3.4's don't have sludge problems with this same cam drive design. JMHO
3.4 fourrunner sludged and smoking, now whats(includes pics)
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I believe the leading consensus on sludging in the 97 to 2002 Toyota V6 is the cooling passages to the heads were reduced in size to increase the head temperature to get a cleaner burn to meet emissions standards which made these engines sludge prone. Claims have been made that the head design allows oil to pool in the top end and the heat cooks it.
The cam gears I believe have been held responsible for a wider range of Toyotas having an oil shearing problem but not directly to the big sludge problem. Though a contributing factor.
Toyota modified the PCV system post mid 2002 which may point to a third contributing factor, but I think was a cheap attempt to compensate for the head temp changes.
plexx, you should be fine but to be sure spend a few bucks and analyze the oil once a year.
In testing the Toyota 3.0L we had issues with M1 adds package coating and begining to sludge in those engines, particularily clogging the small orificed PCV valve.
John Browning is right on. And he's a pro Wrench turner. I am going blind from reading these #'s all day !
I am seeing sludge build up in cars you would never dream it, i.e. BMW's, chrysler, Toyota's, Fords real bad about displaying mositure around the oil filler cap and dipdtick tube on their 2.0L 4 cyl engines.
None of these engines have coolant leaks that we are detecting in analysis.
In testing the Toyota 3.0L we had issues with M1 adds package coating and begining to sludge in those engines, particularily clogging the small orificed PCV valve.
John Browning is right on. And he's a pro Wrench turner. I am going blind from reading these #'s all day !
I am seeing sludge build up in cars you would never dream it, i.e. BMW's, chrysler, Toyota's, Fords real bad about displaying mositure around the oil filler cap and dipdtick tube on their 2.0L 4 cyl engines.
None of these engines have coolant leaks that we are detecting in analysis.
Terry,
Any problems with the 3VZ-E engines?
Any problems with the 3VZ-E engines?
Hey guys and gals I think that someone is trying to turn this into a mystery. If this were coolant in the oil, creating this must sludge, the residue would be light brown in color. This is obviously an engine that has been abused. If your oil has been changed every 5k including a filter I don't care what brand of oil you use it's not going to create this condition. The difference in engine oils is at what point the lube package breaks down. The higher the parafin content, the lower the quality of the package.
Just went to that "sludge zone" site. What a bunch of crap - says that going to the dealer for your oil changes is a sure way to avoid sludge.
Maybe a sure way of preventing Toyota from blaming you for it, but I doubt it's their "factory trained oil change technicians" that are making the difference in this sludge problem.
Once again I am amazed at the scale and scope of unchallenged "infopinion" presented on the internet.
Maybe a sure way of preventing Toyota from blaming you for it, but I doubt it's their "factory trained oil change technicians" that are making the difference in this sludge problem.
Once again I am amazed at the scale and scope of unchallenged "infopinion" presented on the internet.
I'm a little miffed on how the obvious is missed. This toyota issue on sludge is and has been an on going problem. No, not all sludge issues are because of neglect. No, not all sludge issues are because of coolant ingression.
Toyota is the ONLY engine that has those gears on the heads. As Gman pointed out, those gears are notorious for shearing down a normal oil in viscosity. We have evidence that in the normal v6 sludge engines, a 30wt oil(castrol gtx) will shear down from a 30wt to a 20wt just inside of 3500 miles confirmed with oil analysis and no evidence of any contaminants. There is also evidence that shows anyone that did 3k drains did not in-fact have any sludge issues. There is also evidence that only certain engines had this problem and most times it was ones that had tight engine compartments, where air flow was lacking and had smaller oil sump capacities.
Toyota was trying to stay up with other dealers when it came to extending oil drains but failed to recognize just how their engines would affect the oil.
Yes, in my research, I have seen a brand new 12,000 mile engine, totally locked up and blown with sludge at the dealership.
There are certain steps to keeping a toyota from sludging. If standard oil is used, do not go beyond the 3k drain intervals. If going to 5k on up, then a good oil such as schaeffers, amsoil, m1 or redline should be used and those oils will not shear out like most conventional oils.
To those with toyota's and no sludge, I'd put some on the fact that you either following the 3k drain or are using a better than normal quality oil. The evidence has shown that all these sludge engines used weak otc oils and that if anyone had a sludge issue with say amsoil, it was due to trying to do 20k drain intervals.(there was one case like that).
Anyway, That's the skinny on the basic sludge issue. Nothing hard to understand.
Toyota is the ONLY engine that has those gears on the heads. As Gman pointed out, those gears are notorious for shearing down a normal oil in viscosity. We have evidence that in the normal v6 sludge engines, a 30wt oil(castrol gtx) will shear down from a 30wt to a 20wt just inside of 3500 miles confirmed with oil analysis and no evidence of any contaminants. There is also evidence that shows anyone that did 3k drains did not in-fact have any sludge issues. There is also evidence that only certain engines had this problem and most times it was ones that had tight engine compartments, where air flow was lacking and had smaller oil sump capacities.
Toyota was trying to stay up with other dealers when it came to extending oil drains but failed to recognize just how their engines would affect the oil.
Yes, in my research, I have seen a brand new 12,000 mile engine, totally locked up and blown with sludge at the dealership.
There are certain steps to keeping a toyota from sludging. If standard oil is used, do not go beyond the 3k drain intervals. If going to 5k on up, then a good oil such as schaeffers, amsoil, m1 or redline should be used and those oils will not shear out like most conventional oils.
To those with toyota's and no sludge, I'd put some on the fact that you either following the 3k drain or are using a better than normal quality oil. The evidence has shown that all these sludge engines used weak otc oils and that if anyone had a sludge issue with say amsoil, it was due to trying to do 20k drain intervals.(there was one case like that).
Anyway, That's the skinny on the basic sludge issue. Nothing hard to understand.
thanks everyone for the input, I'm still cleaning
the engine out, I'll keep ya'll posted
the engine out, I'll keep ya'll posted
Please hose the valve cover out with water. If it dissolves out, it is dried up cooked coolant residue. If it doesn't it's just tar from the oil. Please try this and let us know.
Leo
From the first few posts, it's evident that the guy said he's not changing the oil every 3k miles. In fact, if it was purchased with about 40k, and then at 76k and four years later we have the problem, the guy is driving about 9k miles/year and doing 1 or 2 oil changes.
But, I do agree with those above that say the residue is too dark to be coolant. At least the coolant or condensation contamination I've seen is closer to mayonaise or a brown color.
Perhaps if let go for a while...
I really don't know.
I'll go back to lurking for a while
TB
But, I do agree with those above that say the residue is too dark to be coolant. At least the coolant or condensation contamination I've seen is closer to mayonaise or a brown color.
Perhaps if let go for a while...
I really don't know.
I'll go back to lurking for a while
TB
Can't agree more with Bobs comment!
His analysis is right on the money! I fault Toyota for not revising there manuals to reflect the 3000 mile or 3500 mile interval on these affected motors. They should send out a special notification. The fact that they havn't has me miffed!
It does no good to ignore problems.
Toyota is expected to live up to high expectations and when they screw up you hear about it. It may be that these vehicles are so "trouble free" that it adds a sense of false security and overall neglect happens.
Toyota is expected to live up to high expectations and when they screw up you hear about it. It may be that these vehicles are so "trouble free" that it adds a sense of false security and overall neglect happens.
Alot of the reason car manufacturers, like Toyota have 5K oil change on severe service and 7.5K on normal service is to get their government (EPA I think) total cost of ownership numbers down. They have these numbers in the manual , but then the dealer tell all their customers(I'm one of them) they need to change it at 3K.
Since these are government posted numbers, I think if Toyota would go back and change them , they might be financially responsible to all of the car owners for the cost of these additional oil changes.
Likewise if Toyota were to recall all these cars and put the mid 2002 PCV mods there is the cost of recertifying all the emissions on these cars in addition to the actually repair costs.
They have decided the cheapest thing is to replace a few thousand engines for the first 8 years (unlimited miles) of the cars life.
Total cost of ownership has nothing to do with gov't. At least one auto manufacturer was honest enough to state "we lowered the cost of maintenance to offset the higher initial cost of the vehicle". Makes me wonder if that person still works for that German auto manufacturer!
I'm glad to see that at least one person did the math and noticed that TIME interval was a little abusive.
Also, the vehicle wasn't a one owner, was it? Anyone want to guess on whether the odometer was tampered with?
I also don't fully fault Toyota for all those so called sludge issues. Still haven't found one in my area that wasn't owner abuse or neglect. I guess that any good lawyer can get a judge/jury to side with consumers. Toyota should've figured that lazy consumers will stretch the maintenance schedules and should've adjusted the intervals appropriately.
I'm glad to see that at least one person did the math and noticed that TIME interval was a little abusive.
Also, the vehicle wasn't a one owner, was it? Anyone want to guess on whether the odometer was tampered with?
I also don't fully fault Toyota for all those so called sludge issues. Still haven't found one in my area that wasn't owner abuse or neglect. I guess that any good lawyer can get a judge/jury to side with consumers. Toyota should've figured that lazy consumers will stretch the maintenance schedules and should've adjusted the intervals appropriately.
Actually the majority fits the "severe service" catagory so therefore the reflection on the intervals should be 3750 "severe service". "Normal Service" is a fraction of the consumers and is under ideal circumstances in order to fit "normal service" schedule. Since the majority do not fit "normal service" its the negligence on the owners part as long as a clarification is made on the terminology of the intervals which will outline exactly what "normal service" is and what owners fit that schedule. Most people will find that they fit the "severe service" schedule when they are properly informed.
If the above clarification is done properly all will be within the scope of consumer, government agencies, etc.
Then again we are only talking about the "affected" motors which are a fractional number if that. Of the fractional numbers involved only a fraction of them stretch the oil changes past 3000 miles.
If the above clarification is done properly all will be within the scope of consumer, government agencies, etc.
Then again we are only talking about the "affected" motors which are a fractional number if that. Of the fractional numbers involved only a fraction of them stretch the oil changes past 3000 miles.
From my "Scheduled Maintanance Guide" for my 1999 Toyota Avalon
That's what they told their consumers. Sorry but under this , soccer moms making 1 mile trips in the summer heat is not Severe service ... according to Toyota. NOT my opinion, just Toyota's.
In short, WHO KNOWS!? . I'm a 99 Avalon owner who was doing 7.5k oil changes on M1 10w30. Now I run Amsoil 0w30 on 5K changes. I have no sludge problem at all ... yet.
I DO think there is an issue. My brother-in-law's 99 RX300 has buildup under the oil fill cap and very dirty oil on his last oil change at a 4k interval. I'm trying to talk him into running a few cycles of auto-rx. He's done 3-4k Jiffy lube changes , but has owned the car only 15K of it's 45K life. I think it was supposed to have good maintanance records.
One of the problems of getting to the bottom of this is there is a certain woman school teacher who has made herself the consumer advocate on this and is heading a class action suit. I won't mention her name, but it will only take 5 minutes searching the web to figure it out. Strangely she did the same thing with Dodge Minivan's back in the early 90's. She has pushed and encouraged so much misinformation on the web, I don't know what are true stories and what is fabricated anymore. I estimate she personally has made about 50% of all toyota sludging postings on the entire web. Probably has her students help her. This is the ONLY site with discussions of this issue where I haven't seen her name.
On the flipside , Toyota denies any problem, but will now fix engines sludged in the first 8 years unlimited miles if you can prove some attempt to change the oil in the last year. In the letter I receive they did not revise their INSANE maintanance schedule of 7.5k with dino for a very loosely defined normal service level.
So I don't know what to believe anymore.
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