Blacktop 20V Sludge?

[monkeymajik]

What is a good method to test if your PCV is blocked?

[c2888]

In my warranty and service manual, it tell of two service schedules.
Normal maintenance and severe conditions.

Severe driving conditions that affect engine oil and oil filter are:
Towing a trailer, using a camper or car top carrier.
Repeated short trips less than 8km and outside temperature remains below freezing.

Under severe conditions it shows that oil and filter change intervals halve to 5000kms.

All motors will develop sludge/buildup if not serviced at the recommended intervals. Even Toyotas!
Most common are the much relied on but sorely neglected Camrys and Corollas that make up the aussie Toyota fleet. But I've seen lots of Celicas too, but they are just Camrys in drag right? /flamesuit ON

I've seen spotless engines at 350000kms in lots of vehicles, most of the ones that make it that far are the commercial vans, Hiaces, Hiluxs etc. Probably because they get serviced properly, if it's your money maker, you take care of it.

The most buildup I've seen was in a SDV10 motor, 5S-FE for the non Camry fans
Buildup was about 10mm off the top of the cam bearing caps

Oil has a finite working life, it contains detergents and conditioners that help reduce and to an extent remove buildup. Run the oil for too long, too long depends on operating conditions, and the oil simply runs out of the additives, so where do all the contaminents go? Straight on the non moving parts of your engine.

Sludge is not so much of a problem, it's more the effect it causes. It insulates the metal that it's covering, so all the bearing caps run a little bit hotter, more heat, engine oil has less working life because of it.

Running the oil level low can also accelerate the engine oils working life, as running at the bottom of the dipstick reduces your capacity by about a litre in most toyotas. With most of them only having a 4 litre sump, you lose 25% of your capacity. So you gain more heat because the oil has to go around more often.

I've seen a fair few import toyota motors that are quite heavily sludged, it tends to be the cheaper more disposable cars that don't get serviced. Mechanics charge heaps over there, and it's probably cheaper to NEVER service your car as you're gonna dump it in 3 years anyway. Lift the oil cap on a 1UZ-FE halfcut and it's pretty much guaranteed to be minty fresh in the valve cover, because they get love as they are expensive to buy.

Go here and read about it more as I'm sure I've forgotten something.
http://www.carbibles.com/engineoil_bible.html

Dan

[3sgte]

not known for it. unless broken.
got busted/lower temp rated thermostat? car not getting up to temp? PCV blocked

Standard thermostat working normally, PCV not blocked.
Replaced PCV, as I am obviously not able to check all aspects of its operation.

c2888:

I appreciate the thoughts, but what you wrote isn't entirely on target, or to the point of my thread here.
In the case of my Corolla, it spent at least 9 years in service in Japan, so I don't think a generalization about being dumped in 3 years is valid.
I have 10 years working at a dealer over here, and I have done at least 20 #mz engines for sludging.

I agree that oil change frequency has a huge effect on sludging, but the fact remains that some engines are more prone to this than others.
Mine is not the first blacktop 20V I have seen with sludge, but I wanted to see if others have experienced this too.

Perhaps others can benefit from this.
It seems that it is necessary to change the oil on a VVT 4AG more frequently than on an older non-VVT 4AG.

Perhaps the intake manifold design, in conjunction with VVT, affects the ability of the PCV on the blacktop 4A-GE to adequtely ventilate the engine. If "adequate" isn't the best word, then I should make the comparison (ie. not as good as the ventilation for the 7A and 4A-FE), as the 4A-FE and 7A-FE have NO sludge tendancies whatsoever.

As for 1UZ, that engine prior to VVT adoption has almost no tendancy toward sludge, after VVT adoption for 1UZ/3UZ, the tendancy increased slightly.

[Trekka273]

I am not sure if the blacktop engine in particular is prone to sludge. The engine I purchased and stripped had no sign of sludge at all. In fact, I was very surprised at how clean the engine was inside, I was expecting there to be some sludge, etc but there was none at all.

I wonder if it could have something to do with how long the engine is left to sit between being sold in Japan and then purchased in another country? Perhaps the time spent not being started, etc and being exposed to varying weather could have some effetc on the oil in the engine? Just a thought...

[allencr]

I can't see it being related to any specific engine, but to its use & maintenance. I used to think it was related to heat that would bake the dirty oil, but twin cams have a lot of temp. difference between the intake & exhaust sides, yet any buildup is just about the same.

More blowby means more carbon & smegma in the oil that will build up another layer every time it cools down.
I'd be surprised if any non-carb has a PVC.