Da Coupe

iTrader: (7)

I have a 98 SC400 with a 1uz vvti motor so I figured I'd post here since all the GS400's are vvti equipped. So the other day I pulled off my intake manifold to access my starter and noticed heavy sludge in all the intake ports of the cyl head (enough to scrape off with a spoon). I decided to split the intake manifold in half in an attempt to trace where the oil is coming from and what do I see? Oil sitting in the bottom of the manifold. Enough to swash around. Please don't tell me this is normal.
Any ideas where it's coming from? The motor has 150k btw.

mtparker18

Bad piston rings? Check your compression.

Da Coupe

iTrader: (7)

Yea I'm hoping it's not the rings. I have the engine on a stand right now and don't have access to a compression tester. I'm wondering if blowby or a faulty pcv can draw that much oil into the intake manifold.

GS4_Fiend

iTrader: (22)

I would change that PCV. Cheap and easy.

ChampGS3

iTrader: (6)

Yes, the vacuum these engines draw at idle along with a stuck open pcv valve and you will gets lots of oil in the upper IM, especially one with an area for it to pool up. It really has nothing to do with your rings though, that would be causing smoke out of the exhaust etc..

I once had a 03 Maxima that I ended up running an oil catch can off the pcv system because that damn thing would suck up a half quart between oil changes. I just got a filter off of a large air compressor from Sears with a little emptying valve at the bottom, Every few weeks I would just take off the oil filler cap, open up the little turn valve and dump this few ounces of oil back in.

I wonder why the engineers aren't worried or don't care about this? Like you, I certainly don't want all that oil in my manifold, probably doesn't really cause much issue in the way of a/f ratios or fuel mileage, so maybe that is why the engineers could care less. I suppose its better to have the crankase properly vented then not?