Timspu

Whilst replacing my fuel linjectors i have noticed residual oil in the mass airflow meter and in the pipe work through the intercooler to the throttle body and inlet manifold.
i am trying to work out if my turbo is leaking oil from the cold side which is entering the intercooler and TB. if so not sure how oil is getting into the mass airflow meter. The Air filter box is dry so i don't think the oil system is breathing.
Any ideas? Does the BOV vent into the air box?
Is there normally oil in the air system of a 930 turbo?

Thanks

TIM

mfyoung1086

Thats not uncommon on turbo cars, nothing to worry about. Just give it a good clean, turbo's will leak a bit of oil over time. If your recirc'ing your BOV back into your intake that would explain the oil getting back into the air box.

If the turbo was leaking badly, your car would be smoking when you run it... You'd prop have some pretty significant shaft play as well

TT Surgeon

Did you overfill the oil recently, that will do it everytime. Ask me how I know......

Timspu

Thanks for the responses, The car has recently had a top end rebuild and is smoking on cold start only, also take a bit of time to start. Warm start is perfect.
I did notice when I collected the car the oil level was full to the top. So this could be the issue of oil in the system, glad to hear they do breath oil. Not sure why she is smoking on start and it does appear to be blue. The cold start AFR is about 10.5 Afr leaning to 13.6 Afr at Idle. I have a leask adjustable Wur, could the initial cold start Afr be too rich at 10.5 Afr Causing the smoke?
Tim

mfyoung1086

Blue smoke would be oil burning, so your turbo seals might just be on their way out. Have you checked shaft play? This is usually a good indicator of the condition the turbo is in

If you have some time, post some pics of how much oil was in the system, it'll give me a better idea of where your seals are at.

As far as your cold start AFR, its not out of parameters some cars cold start closer to 12, some closer to 10, all cars cold start rich

You running the stock turbo? How many miles are on it?

Timspu

I have a stock turbo fitted with has covered 85K miles. The car does not appear to smoke under boost and there is no oil splashes on the rear bumper or engine lid. Since cleaning the IC 100 miles ago there is no further oil in it, yet the mass airflow housing was oily but no dripping.
The engine had new valve guides fitted during the rebuild, could the stem seals be seaping overnight causing the blue smoke. It only smokes from cold and once left overnight.

Cheers

TIM

mfyoung1086

Just sounds like normal oil leak on an 85K mile turbo... This isn't a modern day ball bearing turbo thats gonna give you 100+ trouble free miles

Also just because the compressor side is leaking, doesn't mean the exhaust side is going to as well, but like I said if shaft play is ok, it really sounds like you have minimal leaking anyways, my Saab used to smoke if I left it sitting around long enough, but it had a GT17BB turbo with 173,000 miles on it, and I knew it was leaking from the compressor side, just not enough for me to car, or effect performance

I would just start saving up for a GT35R!!! My favorite turbo ever! Well besides the fact it destroyed my transmission on that same Saab

Timspu

Thanks for your feedback. i will have to take a look at the turbo shaft and confirm.

Cheers and love the colour of your car.

TIM

mfyoung1086

Thanks!

Yeah its an easy enough process just grab the nut on the compressor wheel and give it a shake back and forth, shouldn't play at all

GT35R though trust me! It'll be the last turbo you ever put on that car! BB, great spool, flows tons of CFM

I wouldn't be surprised if it took you up toe 375 380 hp with no other mods, shizz I went from 254 BHP with ~23PSI on my 2.0L saab to 323 on 17PSI when I went to the GT35R

Also I'm a sucker for Guards Red! Great looking turbo car!

Timspu

Have fixed the poor cold start issue. When i started the car from cold the AFR was 10 and raised to 10.4 (<10% CO) after a couple of seconds. This was all done with the electric plug disconnected from the WUR. I then adjusted the cold start adjuster until i got 11.7 AFR (7.5% CO). Attached the electrics and let the car idle. Warm idle is 13.7 AFR (2% CO).
Started the car this morning and it started on the first flick of the key, plus no smoke.
The moral here is that even though a garage says all the fuel pressures are as per the book each engine is individual and mine needed less fuel for the start.

Thanks for all the feedback which helped me rectify this problem.

Cheers

TIM

mfyoung1086

Good to hear she's running well!

Timspu

MFYOUNG 1086, Your info on the cold start AFR pointed me in the right direction.
Thanks again

Eliza Sanchez

Timpsu you are right i also observed this thing while replacing oil. According to me i think it is necessary to use Good quality of oil flow meter which may help to stop the residue ...