F30POST
F30POST
2012-2015 BMW 3-Series and 4-Series Forum
BMW Garage BMW Meets Register Search Today's Posts Mark Forums Read
BMW 3-Series and 4-Series Forum (F30 / F32) | F30POST > Technical Forums > B58 Turbo Engine / Drivetrain / Exhaust Modifications > Strange buzz/knock after turning motor off
Extreme Powerhouse
Post Reply
 
Thread Tools Search this Thread
      09-18-2020, 07:34 PM   #1
therealm3
Major
123
Rep
1,299
Posts

Drives: F30 340 MSport
Join Date: Aug 2006
Location: CA, USA

iTrader: (6)

Strange buzz/knock after turning motor off

Hell all,

I wanted to reach out and see if other have this issue with their B58. Mine started doing it about 9 months ago and the dealer reprogrammed the whole car and Ecu and said it was fixed. It wasn't. I took it back and they replaced the valvetronic motor and said it was fixed. Surprise, it wasn't. Well then Covid hit and didn't drive much at all till a few months ago and was annoyed by the sound enough to take it back. They confirmed the sound but couldn't figure out what to do. Opened a ticket with bmw and they said to reprogram the ecu again and that would do it. I told them to really test the car before the all clear and they allegedly did. A week and a half after dropping it off, I drove it home. The excitement to be back in my car and was immediately let down when I pulled into the garage. Turned off the motor and heard the sound immediately. It varies in length after a drive cycle but it's somewhere in the one minute range. The frequency of the buzz sound can be faster or slower but I can't seem to correlate why.

So, do any of you have this sound and if you do, were you able to get any sort of fix from bmw?

Here is a short clip from under hood with the cover off the top of the motor:



And here is one from outside the car:



Really appreciate any input folks have.

Thanks!
Appreciate 0
      09-19-2020, 07:27 AM   #2
kern417
Cheapskate
United_States
3188
Rep
4,258
Posts

Drives: 2018 440i / 2010 X5
Join Date: Aug 2016
Location: Cincinnati

iTrader: (1)

maybe noisy water pump?
__________________
Quote:
Originally Posted by umizoomi View Post
As long as 3-pedals are an option, I will exercise my right to suffer the handicap and indignity of slower shifts and reaction times.
Instagram @kern417
Appreciate 0
      09-19-2020, 12:16 PM   #3
therealm3
Major
123
Rep
1,299
Posts

Drives: F30 340 MSport
Join Date: Aug 2006
Location: CA, USA

iTrader: (6)

Quote:
Originally Posted by kern417 View Post
maybe noisy water pump?
I suggested that and they keep saying it's the valvetronic motor. To me it makes sense that it could be the water pump given when the noise occurs. I am just hopeful someone on the board has experienced this and can offer some insight. I found one guy on YouTube who posted a video of the same noise last year but he hasn't responded to my inquiry.
Appreciate 0
      09-19-2020, 06:40 PM   #4
weehe126
Colonel
851
Rep
2,724
Posts

Drives: 2016 340i
Join Date: Apr 2014
Location: San Antonio

iTrader: (2)

The water pump is mechanical, not electric on B58s I thought. So there isn't a way it would keep spinning with the engine off. They probably keep saying it's eccentric shaft/servomotor related because this was an issue with N55s. Did they just replace the servo motor or also the eccentric shaft?
Appreciate 0
      09-19-2020, 10:53 PM   #5
440MIA
New Member
United_States
23
Rep
12
Posts

Drives: 2018 440i Grand Coupe LCI
Join Date: Aug 2018
Location: Miami

iTrader: (0)

Quote:
Originally Posted by weehe126 View Post
The water pump is mechanical, not electric on B58s I thought. So there isn't a way it would keep spinning with the engine off. They probably keep saying it's eccentric shaft/servomotor related because this was an issue with N55s. Did they just replace the servo motor or also the eccentric shaft?
The B58 has 3 water pumps (that I know of). One of them is mechanical and the other two are electrical pumps. One of the electrical pumps is for the charged air to water cooler intercooler in our intake plenum. The second electrical pump is for cooling the turbo. Also, if you get the turbo hot enough and turn off the car, the turbo pump will stay on to cool it down.
Appreciate 3
therealm3123.00
kern4173187.50

      09-20-2020, 01:40 AM   #6
weehe126
Colonel
851
Rep
2,724
Posts

Drives: 2016 340i
Join Date: Apr 2014
Location: San Antonio

iTrader: (2)

Quote:
Originally Posted by 440MIA View Post
The B58 has 3 water pumps (that I know of). One of them is mechanical and the other two are electrical pumps. One of the electrical pumps is for the charged air to water cooler intercooler in our intake plenum. The second electrical pump is for cooling the turbo. Also, if you get the turbo hot enough and turn off the car, the turbo pump will stay on to cool it down.
Nice, makes sense. Then would make sense it could be the turbo cooling pump since it's only after shutdown. The servomotor issue would occur before start up (waking the car up), and after locking the car (going to sleep).
Appreciate 0
      09-21-2020, 12:20 AM   #7
therealm3
Major
123
Rep
1,299
Posts

Drives: F30 340 MSport
Join Date: Aug 2006
Location: CA, USA

iTrader: (6)

This is really good info. Thank you!
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 06:23 PM.




f30post
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