Boost leak? Bad PCV?

shyne · 10-04-2024, 04:48 PM

Hello all,

I’m dealing with a couple of issues.

Car is a 07 335i on MHD Stage 2

-Excessive oil consumption
-No boost (.5 psi max)
-Smoke at decel only
-No codes

I’ve tried to smoke test. What I did was block off both inlets where they meet the air box. I took off the pipe that goes from the throttle to the intercooler. I placed the smoke tester to the intercooler hose and ended up getting smoke out of the throttle so I plugged it. After doing that smoke was pushing out of my valve cover and the oil cap like crazy.

I don’t know much about these motors and their systems but that doesn’t seem right.

I have access to ISTA and INPA. I have tried to find test plans to no avail.

Does anybody have any ideas of what I can do to properly diagnose this issue? Like I mentioned I have no codes so this is really throwing me off. The car drives fine, no stuttering or anything. If you didn’t know any better you’d think thats how it drives.

Here is a data log I did a couple weeks ago.
https://datazap.me/u/shyne/log-17267...og=0&data=3-23

Thank you to anyone who tries to help in advance 🙏

Sgop335 · 10-04-2024, 06:41 PM

There is a pcv hose going from the rear turbo inlet hose to the crankcase / valve cover. That way you’re probably pressuring the crank case and smoke coming out of vc and oc...

shyne · 10-08-2024, 12:50 PM

Hello!

Having smoke tested my intercooler piping and the airbox pipes I couldn’t come to a solid conclusion. I decided to test my wastegate rod actuator (before I completely crossed off the turbos as being blown like everyone is quick to do…)

To my surprise they weren’t stuck. I didn’t have my downpipes off to visually inspect the flap was closing properly. I could audibly hear the wastegate close at 7psi which seems to be within spec.

It ended up being a torn vacuum line at my rear turbo wastegate. I replaced the turbo side vacuum lines with 5/32 from auto zone while I order some upgraded 3.5mm later.. Finally hitting target psi.

For some reason this also alleviated the oil consumption and smoke on decel issue I’ve been having. I’m not sure if they are related at all.

I’ll probably look at replacing my valve cover and using an upgraded pcv valve soon. (74k miles)

If anybody has any input that would be greatly suggested!

10-04-2024, 04:48 PM	#1
shyne New Member 23 Rep 27 Posts Drives: 07' E92 335i Join Date: Jan 2023 Location: Northern Virginia iTrader: (0) Garage List 2007 BMW 335i [0.00]	Boost leak? Bad PCV? Hello all, I’m dealing with a couple of issues. Car is a 07 335i on MHD Stage 2 -Excessive oil consumption -No boost (.5 psi max) -Smoke at decel only -No codes I’ve tried to smoke test. What I did was block off both inlets where they meet the air box. I took off the pipe that goes from the throttle to the intercooler. I placed the smoke tester to the intercooler hose and ended up getting smoke out of the throttle so I plugged it. After doing that smoke was pushing out of my valve cover and the oil cap like crazy. I don’t know much about these motors and their systems but that doesn’t seem right. I have access to ISTA and INPA. I have tried to find test plans to no avail. Does anybody have any ideas of what I can do to properly diagnose this issue? Like I mentioned I have no codes so this is really throwing me off. The car drives fine, no stuttering or anything. If you didn’t know any better you’d think thats how it drives. Here is a data log I did a couple weeks ago. https://datazap.me/u/shyne/log-17267...og=0&data=3-23 Thank you to anyone who tries to help in advance 🙏
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10-04-2024, 06:41 PM	#2
Sgop335 Colonel 663 Rep 2,070 Posts Drives: 07 335i e92, 08 535i Join Date: Jun 2014 Location: MD iTrader: (1)	There is a pcv hose going from the rear turbo inlet hose to the crankcase / valve cover. That way you’re probably pressuring the crank case and smoke coming out of vc and oc... __________________ 335i e92 TPC 19Ts
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10-08-2024, 12:50 PM	#3
shyne New Member 23 Rep 27 Posts Drives: 07' E92 335i Join Date: Jan 2023 Location: Northern Virginia iTrader: (0) Garage List 2007 BMW 335i [0.00]	Hello! Having smoke tested my intercooler piping and the airbox pipes I couldn’t come to a solid conclusion. I decided to test my wastegate rod actuator (before I completely crossed off the turbos as being blown like everyone is quick to do…) To my surprise they weren’t stuck. I didn’t have my downpipes off to visually inspect the flap was closing properly. I could audibly hear the wastegate close at 7psi which seems to be within spec. It ended up being a torn vacuum line at my rear turbo wastegate. I replaced the turbo side vacuum lines with 5/32 from auto zone while I order some upgraded 3.5mm later.. Finally hitting target psi. For some reason this also alleviated the oil consumption and smoke on decel issue I’ve been having. I’m not sure if they are related at all. I’ll probably look at replacing my valve cover and using an upgraded pcv valve soon. (74k miles) If anybody has any input that would be greatly suggested!
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