Rb20 Chewing Oil

[Luke HCR32]

My 1992 R32 GTS-T has been consuming oil slowly since I bought it six months ago. It's running an RB20 with stock turbo at stock boost (7 psi approx.) with an aftermarket front mount, it does have a manual boost controller indicating it's probably been boosted in the past.

Recently the rate of oil disappearing has increased massively (about a litre per thousand kms), it doesn't drop any at all so is burning it somewhere.

Today I got around to removing some of the pipework and after removing the elbow which joins the turbo outlet to the cooler through the engine bay wall I found alot of dirt oily residue inside the pipe. Shining a torch down the pipe leading to the cooler showed signs of oily shit running down the pipework towards the cooler (which was only fitted about 2-3 months ago).

Several questions:

Is it possible that this residue is just buildup due to the age of the car and the problem really lies somewhere else?

Is this enough to diagnose the turbo having f**ked seals (I'm hoping it's not the engine internals e.g. valve stem seals/piston rings and have already bought another stock RB20 turbo in anticipation of this)?

Is it likely that the turbo is the only problem?

Would it be necessary to clean out the intercooler or will it flush itself once I stop the leak?

My exhaust tends to blow alot of carbon, would this be caused by the oil burn alone or am I running rich?

I haven't got around to actually getting to the turbo yet but plan to in the next few days.

Any advice would be appreciated.

Cheers,

Luke

[zebra]

Cleaning the piping and intercooler out.

Do a few hundred km's and check again.

Also check and clean the Cam cover breathers, if they are full of oil after that then there is probably a blow-by issue and its pushing oil out the breahters.

[Luke HCR32]

Thanks mate, where are the breathers located? do they plum back to the piping in such a way that they could be causing the problem?

Sorry I'm still a bit green, first RB and first turbo.

[zebra]

Goes from the top of the cam covers down into the turbo intake pipe. Each cam cover is joined by a rubber hose

will try and find a pic for you

[zebra]

See the rubber hoses towards the front of the cam covers...they are the breathers, one on the left is the PCV the other goes to the turbo intake pipe

[Luke HCR32]

So we're talking the largish most frontmost hose on each cover? What's PCV? Do I need to check the one on the left too or only the one on the right?

[zebra]

PCV is Positive crankcase ventilation

You can check if you like, but it has a one-way valve to suck all the crank case gasses out when the engine is under vacuum and the valve closes underboost and the righthand one is used to vent blowby/crank case pressure back into the intake.

This is normally just gas, but can also ingest raw oil etc.

Search these forums for all the oil control issues RB's have.

Will be easier than me trying to explain it.

[Luke HCR32]

Oh ok so the right hand one should be more critical? I'll get onto it tomorrow but probably strip my piping back to my turbo and check the seal as well.

Reckon it's worth slapping my other turbo on regardless if it has less shaft play?

[Luke HCR32]

Keeping in mind that as soon as I fix the oil issue i'm planning to run towards 10 psi.

[zoidbergmerc]

if it aint broke, don't fix it

check them both, check them all! one at a time though so you can remember where they all go

my check if there is any there oil in the water? Frothy white\greeny milkshake like stuff on the cap. What colour is the oil in your piping? is the car using any water?

how often do you have this car at sustained high RPM?

[Luke HCR32]

Car uses no water what so ever, no sign of any oily residue in the radiator.

Car doesn't get much high rpm work, take it through the hills now and then but I don't slide it or do burnouts our anything.

[Luke HCR32]

The oil in the piping is black and seems to have carbon in it

[Luke HCR32]

I'm running penrite semi synthetic 10W-50 by the way

[Luke HCR32]

Got around to taking more of the engine bay apart today.

Cam cover breather hose has a small amount of oil residue in it however the point where this hose plumbs into the intake shows little sign of oil.

Turbo compressor intake shows little sign of oil, turbo compressor outlet has a fair bit of oil in it.

In the process of taking the turbo off, cracked all the manifold bolts, the top oil line, the passenger side water line and the top 4 dump bolts but cant get at the last two dump bolts or the oil drain, will I need to jack up the car and get underneath?