keeps stalling 2-3 times pops in the intake, possible bad MAF?

2003 BMW 325I

170,000 MILES • 6 CYL • 2WD • AUTOMATIC

BHAMDOC1973

MEMBER
2,007 POSTS

I bought this car running rough at cold start, so bad that it keeps stalling 2-3 times before it can stay running while misfiring and feels like there is back pressure because there are pops in the intake. I thought the secondary air may be the issue but based on readings many say MAF could be the issue. So, i unplugged it before a cold start and the issue is almost completely gone. Is it possible the MAF is bad then?

Apr 11, 2024 at 5:51 AM

STRAILER

✓ASE Certified Mechanic
54,832 POSTS

This sounds like a major engine problem to me, which will give strange MAF sensor readings. I would start with a compressor test which this guide can help with:

https://www.2carpros.com/articles/how-to-test-engine-compression

Please get back to me with the readings.

Apr 11, 2024 at 11:24 AM

BHAMDOC1973

MEMBER
2,007 POSTS

Major? The car drives excellent once the MAF is u plugged. I gave no symptoms of anything major, no overheating, no check engine light codes. Once it's unplugged there is no problem driving the car, no misfires, compression is out of the question.

Apr 11, 2024 at 11:40 AM

STRAILER

✓ASE Certified Mechanic
54,832 POSTS

Popping through the intake? Can you upload a video? I cannot see what's going on this is why I ask for videos. Try replacing the MAF sensor to see what happens. Check out the images (below). Let us know what you find.

Image (Click to enlarge)

Professional Diagram for 2CarPros Members
Click here to log in and view diagram.

Apr 12, 2024 at 5:34 PM

Repair Safety Notice: This information is for general instructional purposes only. Vehicle repair can be dangerous. Verify all information, follow manufacturer service procedures, use proper tools and safety equipment, and consult a qualified repair shop when needed.