Oil on Boost(?) sensor after new turbos

[Davez134]

I've tried searching multple times/ways and cannot find if this has already been covered. Stats: 2017, short block replaced under warranty about 12k miles ago. I replaced the stock turbos with Garrett Powermax turbos with all new oil/coolant lines about 3k miles ago. After a few hundred miles, truck was going into limp mode with a message that said "check manual." I cleaned the MAP sensor, as well as the boost(?) sensor before throtttle body and it runs perfect for about 200 miles then it happens again. I installed a catch can, the same scenario hapens again. The MAP sensor is dry but the one before the throttle body is oily. The tube coming from the intercooler is a bit oily, and after removing the inlet tubes to the turbos, I found a bit of oil on the inlet side of the driver's side turbo. Has anyone else experienced this after installing aftermarket turbos? This never happened with the stick setup. I understand blowby oil in the intake manifold, but can't wrap my head around where this is coming from on the intake side. If this has been covered, I apologize, Just can't find anything here. I've also reached out to Full Race, which is where I bought everything from. Thanks for looking!

 

[FordTechOne]

Some oil in the intake tract is normal from the PCV system. MAP sensors are not that sensitive to oil contamination; most vehicles with an actual oil leak/bypass issue will have fouled plugs and leaking CAC tubing well before a MAP issue. I would recommend downloading ForScan, getting a compatible adapter, and seeing what DTCs are actually setting.

 

[Davez134]

Thanks for the reply, I have a snap on scan tool, I scanned it a couple weeks ago. Out of town now so can’t look, but I believe it was P0106 maybe? I’ll confirm when I get home. I think I’m going to clean out all my piping and intercooler too.

 

[Old-Raptor-guy]

The oil in those spots is normal. Let me elaborate.

The PCV system has to "vent" crankcase vapors into the intake system to be burned.

On an turbo engine, under boost the entire intake system post turbo is under pressure. You do not want that pressure going into the crank case.

So there is an valve that closes under boost to prevent boost from going into the crankcase AND allows crankcase pressure to go to the ONLY low pressure (vacuum/suction) source left and that is the turbo inlet. The crankcase vapors will cool off and condense back into a liquid.

This is why I went with a catch can that is connected to both valve covers.

 

[Davez134]

Thank you for that. I like wrapping my head around how stuff works. I was looking at a catch can for the driver side as well.