White Smoke on Idle & Decel 4A-GE Turbo. Need opinion on oil drain.

[ballpencil]

+1 for turbo seal. Does it smoke when your on boost?

no it doesn't as far as i can tell from my rearview mirror. add the fact that it smokes only when it warms up, i guess they rule out the seal?

[thechuckster]

is PCV necessary? i mean, do i need to connect the catch tank to a vacuum source as well such as the compressor inlet?

it's more about ensuring that the crankcase can vent gas buildup (the PCV system using vacuum to scavenge the fumes out when not under boost) - otherwise under boost, the crankcase pressurises and eventually spits oil out a seal.

fwiw, my 3SGTE has a a small vacuum line that goes from cam cover to TB, and a larger vent that feeds fumes ahead of the turbo. When the small line at the TB got blocked up, I got significant amounts of oil entering the turbo via the larger port. As more oil was clogging up the vent (and mesh ahead of it), the crankcase kept pressuring and it started to to squeeze oil out the turbo seals (and then I got busted for excess smoke).

[ballpencil]

update:
drove about 100km just now and it seems the new drain pipe works! other than heavy smoke at idle just once after extended hard driving, i no longer see white smoke along the way. i think the drain line could be bigger and/or more vertical just a tad to be sure but i'm happy for now. perhaps connecting the catch can to the turbo inlet would help..

[feral4mr2]

also you are not supposed to restrict oil flow to a journal bearing turbo.

are you sure? i run a 1 - 1.5mm restrictor on my journal bearing turbo's, nothing larger. and no less than a 5/8 (~16mm) oil return.
*edit* just to back my comment up, if my memory serves me right it was because after lots of research way back when i did my 1st gte that the 4ag oil pressure was too high for use on the turbo with-out a restrictor. */edit*.


only time i've had a 4agte 'smoke' at idle was when i mounted it too low and the return was backing up causeing oil to seep through the seals., once i moved the turbo higher it stopped embarrassing me at traffic lights. same turbo and never had a issue.