VIBE Motorsports
BMW Garage BMW Meets Register Search Today's Posts Mark Forums Read

Go Back   BMW M3 and BMW M4 Forum > BMW F80 M3 / F82 M4 Technical Topics > Engine / Drivetrain / Exhaust / Bolt-ons / Tuning

Post Reply
 
Thread Tools Search this Thread
      08-13-2019, 08:35 AM   #1
NYG
Major
NYG's Avatar
United_States
1003
Rep
1,060
Posts

Drives: '19 Corvette Z06
Join Date: Feb 2017
Location: Brooklyn, NY

iTrader: (0)

What is this sound coming from my M4 at 1800-2000 rpm? And should I be concerned?

BIMMERPOST
     Featured on BIMMERPOST.com
At around 1800-2000 rpm I hear this low frequency wobble sound. As if something is rotating but is not balanced.

I can only conclude a few things:

1) Not the engine as it's fine at idle and higher rpms
2) Not the tires/wheels as this happens on both track and daily sets
3) Not the dct as this happens in all gears, although I mostly hear it in 3rd/4th or 7th but I think that's purely coincidence.

Does anyone else hear this noise? Is this something I should be concerned about? It doesn't really bother me but I want to make sure something more severe isn't going on with my driveshaft or something.

Thanks.
Appreciate 0
      08-13-2019, 01:49 PM   #2
drroc
Second Lieutenant
115
Rep
214
Posts

Drives: 2015 M3 - 6MT
Join Date: Dec 2016
Location: San Jose

iTrader: (0)

Quote:
Originally Posted by NYG View Post
At around 1800-2000 rpm I hear this low frequency wobble sound. As if something is rotating but is not balanced.

I can only conclude a few things:

1) Not the engine as it's fine at idle and higher rpms
2) Not the tires/wheels as this happens on both track and daily sets
3) Not the dct as this happens in all gears, although I mostly hear it in 3rd/4th or 7th but I think that's purely coincidence.

Does anyone else hear this noise? Is this something I should be concerned about? It doesn't really bother me but I want to make sure something more severe isn't going on with my driveshaft or something.

Thanks.
Is it during light throttle application and sounds like a putt, putt , putt type noise?
Appreciate 0
      08-13-2019, 05:03 PM   #3
NYG
Major
NYG's Avatar
United_States
1003
Rep
1,060
Posts

Drives: '19 Corvette Z06
Join Date: Feb 2017
Location: Brooklyn, NY

iTrader: (0)

Quote:
Originally Posted by drroc View Post
Is it during light throttle application and sounds like a putt, putt , putt type noise?
Yes, very light throttle so that it holds at around 2k rpm.

It's hard to phonetically type out the sound. This video is really close:



But without the high frequencies. Almost like you're rotating something on a string. No metal on metal noises. Just this wobble type sound.
Appreciate 0
      08-13-2019, 06:08 PM   #4
drroc
Second Lieutenant
115
Rep
214
Posts

Drives: 2015 M3 - 6MT
Join Date: Dec 2016
Location: San Jose

iTrader: (0)

If you open your windows and drive close to a wall/divider at 20~30mph at 1800rpm and apply the throttle, you should hear that noise pretty well. So I am pretty sure it is an exhaust leak from the down pipe to the mid pipe. I am dealing with the same issue. I have loosened up the bolts and re-tightened them, and the noise went away. It is now back. So I'll have to get the gasket, and replace it.
Appreciate 0
      08-13-2019, 10:58 PM   #5
NYG
Major
NYG's Avatar
United_States
1003
Rep
1,060
Posts

Drives: '19 Corvette Z06
Join Date: Feb 2017
Location: Brooklyn, NY

iTrader: (0)

Quote:
Originally Posted by drroc View Post
If you open your windows and drive close to a wall/divider at 20~30mph at 1800rpm and apply the throttle, you should hear that noise pretty well. So I am pretty sure it is an exhaust leak from the down pipe to the mid pipe. I am dealing with the same issue. I have loosened up the bolts and re-tightened them, and the noise went away. It is now back. So I'll have to get the gasket, and replace it.
I'm not so sure this is the sound I'm hearing though. I'll look under my car tomorrow. When you're driving with your windows up and music off, do you hear that rotating sound I'm describing at like 2000 rpm?
Appreciate 0
      08-14-2019, 01:42 AM   #6
drroc
Second Lieutenant
115
Rep
214
Posts

Drives: 2015 M3 - 6MT
Join Date: Dec 2016
Location: San Jose

iTrader: (0)

Quote:
Originally Posted by NYG View Post
I'm not so sure this is the sound I'm hearing though. I'll look under my car tomorrow. When you're driving with your windows up and music off, do you hear that rotating sound I'm describing at like 2000 rpm?
There is no mechanical rattle like in the video. Its more like a pulsating sound during throttle application. Its most audible at slower speeds with windows rolled down. However, I am pretty sure it is from the downpipe to midpipe junction.
Appreciate 0
      08-14-2019, 07:56 AM   #7
NYG
Major
NYG's Avatar
United_States
1003
Rep
1,060
Posts

Drives: '19 Corvette Z06
Join Date: Feb 2017
Location: Brooklyn, NY

iTrader: (0)

Quote:
Originally Posted by drroc View Post
There is no mechanical rattle like in the video. Its more like a pulsating sound during throttle application. Its most audible at slower speeds with windows rolled down. However, I am pretty sure it is from the downpipe to midpipe junction.
So I'm hearing it with my windows up but I have a little less sound insulation in my CS. I want to lift the car and check this area. Would there be water coming out on a cold start in that area? Or would I have to have someone give it a few revs to see.
Appreciate 0
      08-14-2019, 12:16 PM   #8
drroc
Second Lieutenant
115
Rep
214
Posts

Drives: 2015 M3 - 6MT
Join Date: Dec 2016
Location: San Jose

iTrader: (0)

Quote:
Originally Posted by NYG View Post
So I'm hearing it with my windows up but I have a little less sound insulation in my CS. I want to lift the car and check this area. Would there be water coming out on a cold start in that area? Or would I have to have someone give it a few revs to see.
Before I redid the bolts, I could also hear this noise quite well with the windows closed. Now, I need to open the windows to hear the noise. Yes, there should be a few droplets of water that come out from that area. You should be able to see them on the floor. Obviously, asking somebody to start the car when it is lifted and gently push the throttle a few times will help.
Appreciate 0
      08-17-2019, 10:08 PM   #9
NYG
Major
NYG's Avatar
United_States
1003
Rep
1,060
Posts

Drives: '19 Corvette Z06
Join Date: Feb 2017
Location: Brooklyn, NY

iTrader: (0)

Dealer says no leaks.
Appreciate 0
      08-19-2019, 03:40 PM   #10
drroc
Second Lieutenant
115
Rep
214
Posts

Drives: 2015 M3 - 6MT
Join Date: Dec 2016
Location: San Jose

iTrader: (0)

Quote:
Originally Posted by NYG View Post
Dealer says no leaks.
But I assume the noise is still present, right?
Appreciate 0
      08-19-2019, 05:02 PM   #11
NYG
Major
NYG's Avatar
United_States
1003
Rep
1,060
Posts

Drives: '19 Corvette Z06
Join Date: Feb 2017
Location: Brooklyn, NY

iTrader: (0)

Quote:
Originally Posted by drroc View Post
But I assume the noise is still present, right?
As of right now, I had MP HAS installed, oil flush, rear diff fluid flush. I haven't heard it yet but I'll need a few days of driving to see.
Appreciate 0
Post Reply

Bookmarks

Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off



All times are GMT -5. The time now is 11:39 PM.




f80post
Powered by vBulletin® Version 3.8.11
Copyright ©2000 - 2020, vBulletin Solutions Inc.
1Addicts.com, BIMMERPOST.com, E90Post.com, F30Post.com, M3Post.com, ZPost.com, 5Post.com, 6Post.com, 7Post.com, XBimmers.com logo and trademark are properties of BIMMERPOST