cause found for engine sludge problem?

[snipped]

Boy, you're really looking for a flame war on this aren't you? This has been rehashed over and over and over again. Perhaps a Google Groups search on this topic would be in order.

It is not my intent to start a flame war over this, believe me.

I found the yotarepair.com site while looking for more information (actually, found it while looking for "the correct way" to clean the idle air control valve), but apparently I've only touched the tip of the iceberg of the engine sludge problem.

My dad has a 2001 camry, bought it in June 2001, hasn't had any engine sludge problems, hoping it stays that way.

So, are you saying the yotarepair.com article is incorrect?

I dug these comments out too about 2 yrs ago from the same mechanic's site. The salient point appears to be: if the engine oil is changed at the specified intervals or less,..the deposits dont occur anywhere near enough to stuff the engine. I note he says he is seeing engines with problems that have been serviced properly,..I can only wonder why.

I bought a '96 -155,000ks with tar and sludge in the engine (I found later). Since owning it (21/2 yrs) I have put 20,000ks on it and there is no increase in the deposits,..why? because I dont allow the oil to get so filthy that it leaves black, carbon particle-loaded deposits in the engine,..it is that simple. Your dip-stick tells you when your oil needs changing.

Now I concede there maybe a PCV loss of function in this saga,..and that situation maybe making the engines less tolerant of lack of oil-changes,..but the proof is in the eating. Keep the oil in good condition and there's no problem.

Jason

Would a more frequent oil changeout (every 3000 miles, say, instead of the 5000 to 6000 miles) help to remove any sludge which has already built up?

Here we go.....

The PCV breathing system is absolutely to blame - that is why replacing the valve covers on the sludge repairs is mandatory. One point that I usually bring up here is that I have been dealing with Toyotas sludge problem since the first 1MZs first started coming in with goo in the valve train, and I nor the dealer I work for has seen one case of sludge in any vehicle accompanied by a consistent service history of 7500 mile (or less) oil changes. Not to say that Toyota isn't to blame at all, it's just that it seems to me that those that followed the service recommendations don't have this problem. So, my conclusion is that these engines have a much lower threshold for neglect than others, a situation easily avoided if proper maintenace is performed.

For those idiots out there that always pile on me for this observation, relax. It's only that; an observation. Don't worry, I'm not a mole for Toyota spreading propaganda and pushing their evil agenda, so save it. It's only my opinion. Just happens to be one with more direct experience than the 'theorists' out there.

The crankcase ventilation system is what the problem turned out to be in my 2000 Avalon (bought used at 70,000 miles). That said, I suspect the direct cause of my problem (sludge clogging the baffles in the valve covers) was lack of routine oil changes by the previous "owner", who was actually leasing. That coupled with a crankcase ventilation system not tolerant of poor maintenance is what caused the sludge, that clogged the baffles, that forced oil into the intake manifold, causing high oil consumption (about one quart every 150 miles) and smoke from the exhaust.

In my case, the dealer (under warranty) replaced the block with a Toyota rebuild, rebuilt the heads, but used the original valve covers.

Amazingly, the oil consumption problem was exactly the same after the rebuild as it was before!

After reading posts on this group, I learned about the valve cover baffle problem, told the dealer, he checked with Toyota, and they said to replace the valve covers with the redesigned ones. They did that, and that is what cured the problem.

I suspect they could have simply replaced the valve covers, without replacing the block and rebuilding the head, and solved the problem, but since all the work was done under a Toyota extended care warranty, I am happy to have a completely new engine.

Now, about that whine in the transmission...

Merritt

It depends on the amound of gel present in the engine. I've sent more than a few people on thier way with instructions to change their oil 5 times in the next 10k miles, but only those with no excessive oil consumption, and only after inspecting the valve train area and looking in the oil pan (either with a boroscope or removal) to confirm that gel build up does not warrant a teardown. Inspection after that period showed a drastic reduction in accumulation. I've also heard (though never observed myself) that BG MOA is particularly good at disolving some light get build up as well.

responsibility.

No it would halt it IMO.

In my engine's case,.I change the oil every 2000 miles ($20 for oil and filter) because it does urban driving most of the time and by 2000 miles the oil has started going black. The engine is not probably in the greatest of condition,..but it had good power and economy.

Jason

This is an interesting article:

It mentions that only the "Toyota or Lexus from model years 1997 to

2002 that use the 3.0-liter V6 engine, and any Toyota from 1997 to 2001 that uses the 2.2-liter four-cylinder engine" are affected by sludge.

It also mentions that "It's worth keeping in mind that, at least so far, Toyota reports about 3,400 sludgy engines out of about 3.3 million sold. So these are still excellent cars, in our opinion, and we'll continue to recommend them."

That's about 0.1%, not the 10% I had envisioned in my mind.

So my question is, starting in 2002, are the 4-cylinder engines now "safe", that is, are there any reported sludge problems with these engines (assuming the engines have been properly maintained)?