What is this sound when decelerating?

pysical

Sergeant
Jun 16, 2017
345
73
0
Ride
2009 335xi E90
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?
 
Last edited:

doublespaces

General of the Army
Oct 18, 2016
8,937
4,143
0
AZ
Ride
2009 E93 335i
If you were able to give a sense of direction that my help. Sounds like your car is sputtering
 

R.G.

Lieutenant
Nov 17, 2016
669
325
0
Henderson, NV
Ride
E92 335, F10 M5
Try to describe what you're hearing.
We won't judge you for using kindergarten type words like screeeech, or vizzzzz...
Mechanical? Metal on metal? Humming, grinding, faint rattle, spooky ghost noises?
 

pysical

Sergeant
Jun 16, 2017
345
73
0
Ride
2009 335xi E90
I will try to take another video tomorrow once the car is together. I did some more investigating and I think it is exhaust related and sounds like something is rattling.
 

335i_lou

Specialist
Nov 13, 2016
83
31
0
Raleigh, NC
Ride
E90 335i, FBO, inlets, outlets
Look up some videos on YouTube of wastegate rattle and see if it matches.... that’s what it kinda sounded like to me. But like everyone else has said that video has a ton of wind noise and is hard to tell.
 

matreyia

Major
Apr 19, 2017
1,746
685
0
Ride
335i e93
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?
Please list mods and upgrades. Including transmission.
 

pysical

Sergeant
Jun 16, 2017
345
73
0
Ride
2009 335xi E90
New video..

It sounds like it has something to do with exhaust. Or atleast the noise is traveling through it. I checked the hangars and nothing. I checked the 4 downpipe bolts and nothing. I put a metal bar against stuff to try and feel the vibrations but I can't feel it anywhere.

I can stick the bar on the actuator rod of the rear turbo and I can feel it vibrate as I hear the noise. I have CP-E Hi Flow downpipes (unknown mileage). The turbos are GC. Transmission is 6MT with Spec S3+ Clutch and Spec SMFW. You should be able to hear it much better in this video.

I emailed VTT and they told me they have not had any complaints of wastegate rattle on the GC.
 
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camberadam

Sergeant
Feb 15, 2017
257
106
0
Baltimore
Ride
Tasmin Green e92
New link doesn't work for me... If it's exhaust related; I was thinking, make sure you have clearance between your pipes & the rear under body brace. I remember when I initially installed the cat back it sagged before I got everything tight; didn't rattle stopped but would here it driving when the piping moved around. Just a thought.
 

pysical

Sergeant
Jun 16, 2017
345
73
0
Ride
2009 335xi E90
Updated. Sorry about that.

EDIT: Also, I just flashed the car again with the wastegate fix. This time I did half way between less lag and less rattle. The sound got louder.

After unhooking the vacuum line from the rear turbo and hooking it directly to vacuum the sound went away. Wastegate rattle it is...
 
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pysical

Sergeant
Jun 16, 2017
345
73
0
Ride
2009 335xi E90
Anyone know of some things I can do to get rid of this? On my custom tune it rattles on decel and accel. I have tried using MHD but it just makes it worse. I have put MHD Stage 2+ on it helps it. I can just barely hear it.
 

matreyia

Major
Apr 19, 2017
1,746
685
0
Ride
335i e93
Anyone know of some things I can do to get rid of this? On my custom tune it rattles on decel and accel. I have tried using MHD but it just makes it worse. I have put MHD Stage 2+ on it helps it. I can just barely hear it.


If software dont fix it, you have you physically adjust it. But I am not familiar with the procedure.
 

pysical

Sergeant
Jun 16, 2017
345
73
0
Ride
2009 335xi E90
I would talk to VTT and see what they say first before touching them.

Yeah I have. I am just looking for other ideas if anyone has ran into a similar problem. I am no way bashing VTT at all. I am just paranoid.