bought car with desludged engine

[13438chris]

A couple of weeks ago I bought a 98 camry w/auto and v6 engine with 87K and very nice condition, had a new steering rack, water pump,timing belt and window regulator installed. i went to toyota dealer after I bought it to see what work had been done to it such as transmission flush and found out the car had been "desludged per ZT3" at 43K miles in 2002 because of blue smoke out tailpipe for $2600 but was under waranty. I asked what was done and was told new piston rings and clean up. I am nervous about the car now, it runs fine but am concerned that sludging will come baack, dealer said i could use BG moa oil supplement to help. Do you think when they desludged engine that any modifications were done to prevent it in the future. I asked about synthetic oil and he said that was not advisable. Any thoughts or suggestion?

[cf99]

Was this person at the dealer that recommended an oil treatment but advised against synthetic oil a Toyota mechanic?

[13438chris]

He was not a mechanic , he was the supervisor/ scheduler

[fenixus]

on a side note. if owner was chaning oils (recommended type) at toyota recommended intervals, they should have done it (desludging) for free under warranty (8 years, unlimited miles) ... that's a result of a class action law suit ... however I think it went into effect after 2006 though ... could be worth asking if they can refund the charges

[13438chris]

I probably was not clear but the desludging was no charge but was valued at $2600 for piston rings etc.

[fenixus]

Originally Posted by 13438chris

I probably was not clear but the desludging was no charge but was valued at $2600 for piston rings etc.

ah, OK

I wouldn't worry about it much. they replaced rings and probably double checked all other stuff too while engine was torn into pieces.

[cf99]

re: "Do you think when they desludged engine that any modifications were done to prevent it in the future."

I don't think there are any "official" modifications to the sludge-prone engine, but Toyota obviously changed something in the next generation since it's no longer a problem.

The closest thing I've been able to find on modifications to the sludge-prone V6 is in this article:
http://www.schleeter.com/oil-sludge.htm

where it says:
"Toyota has a little-known, updated valve cover replacement part for the V-6 engine ($520) to increase PCV system efficiency."

Anyone know about this? I wonder if the dealer did this replacement under the $2300 warranty work your previous owner had done. Can you post pics of your valve covers?

[13438chris]

everybody around seems to go with synthetic oil, wonder why dealer says not to. Was tempted to remove front valve cover to check for sludge to have piece of mind or confirm i have problem.

[fenixus]

Originally Posted by 13438chris

everybody around seems to go with synthetic oil, wonder why dealer says not to. Was tempted to remove front valve cover to check for sludge to have piece of mind or confirm i have problem.

oh, really there is no conspiracy theory behind Toyota not recommending the synthetic oils for gen3/4 engines ... they simply have never lab tested them back then with those engines and manuals only recommend whatever they tested it with at the time of writing it.
since camry is an economy class family sedan, they probably wanted to run it on cheapest oils.

now, they are focused on testing new engines for new oil formulations and gen3/4 are long forgotten and it would be a waste of money for them to retest everything.

bottom line is that service advisor will only advise whatever the manuals say and nothing else or it will be "not recommended".

another (hardcore) reason is that they want to sell as many as possible of new cars and forget the old problem which ended up with a lawsuit... so there is really no business for them to advice people to run better oils in them (and keep their old cars indefinitely) ... and they have good reason for it, engine were not tested at factory with those oils ... it doesn't mean though they can't run on them ... just my opinion.

[cf99]

This article ( http://www.yotarepair.com/Sludge_Zone.html ) claims to know an engine-design-related cause for the sludge:

"The actual cause of the problem is an inability of the engine's crankcase ventilation system (PCV) to move the normal gases from the engine. When these gases stay longer in an hot engine it allows deposits to form on the metal parts of the engine. When enough deposits are present "Sludge" is formed. "

this would at least be in agreement with the quote in my other post above, noting a new valve cover / PCV

[fenixus]

that is entirely true. also many people suspect lack of the oil cooler on gen4 to be at least partially responsible.

anyways, I've seen the PCV poor ventilation argument on a few websites regarding gen4 camry, like BITOG discussions and some blog. that's why it's crucial to keep funtional and clear PCV valve and breathing hoses, there is 2 of them, one from PCV valve to intake manifold and second one from valve cover to intake tube.

someone on BITOG posted that there is a small orifice valve between the breather hose and intake hose (where they inter-connect) and that orifice may be often getting plugged causing poor ventilation (on top of PCV valve and hose on the other side).

revised valve cover idea seems interesting though

Originally Posted by cf99

This article ( http://www.yotarepair.com/Sludge_Zone.html ) claims to know an engine-design-related cause for the sludge:

"The actual cause of the problem is an inability of the engine's crankcase ventilation system (PCV) to move the normal gases from the engine. When these gases stay longer in an hot engine it allows deposits to form on the metal parts of the engine. When enough deposits are present "Sludge" is formed. "

this would at least be in agreement with the quote in my other post above, noting a new valve cover / PCV

[13438chris]

I had actually ordered a pcv valve from dealer yesterday, and wiil inspect pcv hoses when i install it......thanks I'm considering going to synthetic oil, i've heard that there may be more chance of oil leaks though.

[DarkSideMoon]

Mobil 1 synthetic is all I run in my 93 3vz-fe.

[fenixus]

true, synthetic will help prolong motor oil life at least double against conventional oil which eventually cooks (the worse the longer you run it).

pay attention to valve cover gaskets, they like to seep if they are original or old. dino oil deposits maybe only thing which makes them sealed and that will get washed away once you switch (not at once though).

sometime oil pan gasket starts seeping a little, but more often it's the old crank/cam seals (timing area) leaking oil above and making it look like pan's gasket was bad.

if seals and gaskets are not the problem then I can't see anything against using full synthetic oil. I would stick to ILSAC GF-3 & 4 though. GF-5 might be too thin for those old engines, just my 2 cents.
I think there is a reason why reputable Amsoil and M1 full synthetics in HM version are still ILSAC GF-3. again I might be wrong on that, just my personal opinion.

Originally Posted by 13438chris

I had actually ordered a pcv valve from dealer yesterday, and wiil inspect pcv hoses when i install it......thanks I'm considering going to synthetic oil, i've heard that there may be more chance of oil leaks though.

[toddub]

There is a commercial on TV for Castol GTX Oil that claims to prevent sludge build up. You may have seen the commercials where the 2 guys get dumped on with sludge.

You Tube

You Tube

This is a UK sludge commercial

You Tube

You Tube

They say they have tests to back up their claims.