What is this sound when decelerating?

[pysical]

Trying to determine what this sound is. It happens when I am around the 1200 RPM mark and decelerating. You can hear it mostly at the follow second marks.


5-6 seconds
13-14 seconds
30-32 seconds
42-43 seconds

Any ideas?

 

[335i_lou]

Paranoid about what...? If VTT said try adjusting the wastegate actuator, try it out and see if it helps. If it does help, you know what the problem is. The issue is that if it does help, it’ll only last for a little while and then you’ll be back to where you are now. I could be wrong, maybe it’ll fix the problem completely.

 

[pysical]

I unhooked the down pipe from the rear turbo and used a mini USB camera to look inside. I pumped it up to 5.9 inches of vacuum and the waste gate seals like it should. I played around with different amounts and how the waste gate functions and it looks like it is doing what it is supposed to. So moving on, this sound must be something else. If anyone has any ideas let me know.

 

[R.G.]

Ok I hear it. Blow off valve or recirc? Check there first

Have someone tap the revs like you did in the vid and see if you can pin point the area noise is coming from

Use a mechanic stethoscope ( hose on your ear )

 

[dyezak]

It's the dikfer.