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Discussion Starter #1
See pic. I've got some oil coming through this fastener. The volume in this pic is after a twenty minute drive for reference so not much but not exactly dry.

Is that enough to cause lean conditions?

I don't think it is but figured I'd poll the group. New CCV, already smoke tested, etc. so I wanted to ask.

I'm going to have another post later that's more in depth with Fusion logs and the like but wanted to ask this one quickly.
 

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I don't think this very small leak can cause enough air entering the crankcase to cause too much air bypass the air mass sensor and upset the mixture.
 

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2003 325i (M54B30 swap)
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I would say probably not. It could, and obviously and leaks post-TB upset the engine management and running condition much more than pre TB leaks. When my car was running so lean the engine would miss and backfire through the intake, I replaced the VCG and the rubber grommets for the bolts. Sometimes you even can have cracks in the plastic valve cover that you can’t easily see from the top. Again, purely based on your picture that’s probably not leaking enough to matter much, but it certainly could be.
 

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You’ve got lean error codes? P0171 and/or P0174?
 

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E30M3 Race F10 535 R1150Rt M Coupe
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Positive pressure and negative have two distinct differences

Tantamount to a A/C system that holds vacuum but leaks freon. And/or the other way around.

The cover could leak a little bit of oil but has the potential to suck quite a bit of false air.

My point is looking at a oil leak and trying to judge how much vacuum it's pulling is sort of fruitless.

I love these guys with hands on the oil fill cap and saying it's good. I check them all the time with a manometer, my trained hands still can't tell me how much vacuum is the engine pulling.
 

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Discussion Starter #9
Positive pressure and negative have two distinct differences

Tantamount to a A/C system that holds vacuum but leaks freon. And/or the other way around.

The cover could leak a little bit of oil but has the potential to suck quite a bit of false air.

My point is looking at a oil leak and trying to judge how much vacuum it's pulling is sort of fruitless.

I love these guys with hands on the oil fill cap and saying it's good. I check them all the time with a manometer, my trained hands still can't tell me how much vacuum is the engine pulling.
That's a good point Don, thank you. The valve cover does have new gaskets so I'll pull it off to make sure everything is seated correctly.
 
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