jeroentje.nl

setup:

Garrett GT35R
stock engine
oil filler neck vented outside with oil catch can.

I had very high crankcase pressure at boost.
oil blowby... catch can was filled in just a few pulls.

Brand new Garrett GT35R turbo was broken.
There was no oil leaking into the compressor because I used a restrictor.
So oil pressure after the restrictor is to low to push through the bearing.
but the compressor will push air through the bearing into the oil return line causing high crank pressure.

I thought... lets post it because when somebody searched on high crakcase pressure will learn some more and maybe solve the problem.

PandazRx-7

iTrader: (18)

After reading on this subject extensively... I think the best thing you can do is vent BOTH sides of the motor. For single turbo set-ups, you can use the un-used rear oil drain as a vent to a catch can as well as the oil filler neck to the catch can to do this. Some people have also tapped the front cover to achieve this...

jeroentje.nl

I used the second oil return hole also to vent.
But that is not what this topic is about.

High crankcase pressure when you have a good venting system.

I even had a oil cap with the vent tube in the middle...so for high G cornering.
But I had oil blowby at boost on a straight road.

classicauto

iTrader: (3)

Is it burning oil at all?

jeroentje.nl

nope... no oil burning

But it is solved... I just posted it so if someone has a same problem he or she will find this topic and see that the turbo maybe has a broken oil seal.

I thought a lot what it could be.

crankcase was venting perfect.
no oil burn.. so no sideseal
no oil in intercooler
lots of air pressure in the crankcase
I thought it was the turbo but is was brand new... so doubts.

Then I blocked the compressor in en outlet.
put a small hose on the outlet... and blow in it.

Then I noticed air was coming out of the oil return line.
It was very easy to blow throught it.
So emagine what a the compressor house whould do when it hit boost.

When we started the car the first time and let it idle for a while everything was ok.
When I turned the throttle a little en revved it sometimes.. there where some small oil drups in the inlet of the compressor.
So I thought ... broken turbo.
Returned it to Garrett... pulled it appart.... no signes of leakage.
So put it all back together on to the car.
then I went out for a drive.... boosted a few times.. and have a lot of oil coming out of the catch can.

This is the story.... problem solved. Now other can lurn from it.

btw i'm no newbie: http://www.jeroentje.nl/index.php?pa...view&car_id=12