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      11-23-2020, 06:51 PM   #1
Enlisted Member

Drives: 2007 328xi E90
Join Date: Sep 2019
Location: Vienna, Virginia

iTrader: (0)

Diagnosing Stubborn Vacuum Leak

Hey All, need some assistance diagnosing a stubborn vacuum leak that is keeping my Bimmer in the garage since the emissions can't be passed on it.

Unfortunately a lot of work has been recently done so its hard to trace. 2007 E90 XI 100k

- VCG was replaced but it shows no signs of leakage and I think its ok
- Replaced Air Filter with a washable/permanent one and have heard some say it could be a problem.
- Replaced MAF in an effort to correct the unmetered air. I used a Amazon non-OEM part but I don't think its the issue
- Checked airbox, clamps and hoses for leaks but turned up nothing.
- Tried the old spray soapy water trick and it didnt work. Don't hear any air intake.
- Vacuum pump replaced - no affect.
- Resetting doesn't seem to help and it returns

Car runs normally and gets regular gas mileage so I think its a BS warning. Any tips? Should I get the Carly App to diagnose it?