Welcome to Bimmerfest -- The #1 Online Community for BMW related information! Please enjoy the discussion forums below and share your experiences with the 200,000 current, new and past BMW owners. The forums are broken out by car model and into other special interest sections such as BMW European Delivery and a special forum to voice your questions to the many BMW dealers on the site to assist our members!

Please follow the links below to help get you started!

Go Back   Bimmerfest - BMW Forums > BMW Model Discussions > 3 Series / 4 Series > E46 (1999 - 2006)

E46 (1999 - 2006)
The fourth generation 3 Series (E46 chassis) was introduced in 1999 and set the standard for engineering and performance during it's years of production including being named to Car & Driver's 10 best list every one of those years! ! -- View the E46 Wiki

Reply
 
Thread Tools Display Modes
  #1  
Old 10-01-2011, 03:03 AM
gazbell02 gazbell02 is offline
Registered User
Location: Manchester
 
Join Date: Oct 2011
Posts: 2
Mein Auto: BMW M3 E46
HELP! Knocking noise!!!

there is a knocking noise coming from the engine under acceleration but not when stationary? the oil level is fine, the water level is fine, and it doesn't make the noise when revving stationary either.......... as soon as i press the accelerator in gear it knocks under light acceleration but heavy aceleration doesn't make a noise????
Reply With Quote
Advertisement
  #2  
Old 10-01-2011, 06:27 AM
SJBimmer's Avatar
SJBimmer SJBimmer is offline
Living Life At The Beach
Location: In This Place
 
Join Date: Feb 2007
Posts: 3,810
Mein Auto: 2004 325 Convertible
Diagnosing a noise like this is difficult, so you will probably have to try different things. Have you looked at the motor mounts? Sometimes they will only make a noise when under load. If you put the car in gear and lightly try to accelerate, does the engine seem to move up more than it should? This MAY be a sign that the mounts are partially torn, and could cause a clunk or knocking. Check every bolt under the car to see if something is loose. You may also want to have the subframe inspected for tearing. Not sure about the M3, but this was a problem on some E46 models that was addressed by a recall although I believe the free remedy from BMW has expired. Just a few random thoughts to try and help you narrow it down.
Reply With Quote
  #3  
Old 10-01-2011, 09:27 AM
gazbell02 gazbell02 is offline
Registered User
Location: Manchester
 
Join Date: Oct 2011
Posts: 2
Mein Auto: BMW M3 E46
i have listened to the noise and it speeds up with the engine but doesn't when stationary. its like about 2-3000 rpm when i press the pedal. lets say 20-40% of the pedal being pressed. so i can drive it without it doing it but as soon as i press the pedal 20% or more it knocks with the piston speed.
Reply With Quote
  #4  
Old 10-01-2011, 03:27 PM
SJBimmer's Avatar
SJBimmer SJBimmer is offline
Living Life At The Beach
Location: In This Place
 
Join Date: Feb 2007
Posts: 3,810
Mein Auto: 2004 325 Convertible
You may want to check to see if the exhaust is touching anything. I had a knock that was similar after the dealer worked on the car. They had to drop the exhaust to repair the car, and did not position the exhaust correctly. Sorry I can't give you an exact cause, but this is kind of hard to diagnose without seeing or hearing it. I can tell you that my noise was RPM dependent also, and only did it when the car was moving. There was no noise when revving in neutral.
Reply With Quote
  #5  
Old 10-02-2011, 06:30 AM
jshough jshough is offline
Registered User
Location: NC
 
Join Date: Dec 2010
Posts: 12
Mein Auto: 00 528i Sport Pkg (E39)
Hard to diagnose knocks and pings but if this happens while under moderately heavy acceleration, I am going to say to check your center bearing and guibo (pronounced jew-bow). These are pretty easy to replace if you can safely get the car up off the ground and supported so you can safely work on it (ALWAYS use jack mounts and heavy duty jack, NOT your BMW jack)! Bluebee has a great link for these here (thanks Bluebee).
Reply With Quote
  #6  
Old 10-02-2011, 07:56 AM
SJBimmer's Avatar
SJBimmer SJBimmer is offline
Living Life At The Beach
Location: In This Place
 
Join Date: Feb 2007
Posts: 3,810
Mein Auto: 2004 325 Convertible
Quote:
Originally Posted by jshough View Post
Hard to diagnose knocks and pings but if this happens while under moderately heavy acceleration, I am going to say to check your center bearing and guibo (pronounced jew-bow). These are pretty easy to replace if you can safely get the car up off the ground and supported so you can safely work on it (ALWAYS use jack mounts and heavy duty jack, NOT your BMW jack)! Bluebee has a great link for these here (thanks Bluebee).
Thats a great point! Very possible this could be the cause.
Reply With Quote
  #7  
Old 10-02-2011, 09:53 AM
jshough jshough is offline
Registered User
Location: NC
 
Join Date: Dec 2010
Posts: 12
Mein Auto: 00 528i Sport Pkg (E39)
The good news too is if you DIY this it's a max $175 job. I had to get someone to replace mine b/c wife was stuck and I was OOT but it is only about $100 for parts (use pelicanparts.com). My local shade-tree completed the work for $300 which is also reasonable.

Good luck.
Reply With Quote
  #8  
Old 12-16-2011, 01:48 PM
craigbmw325 craigbmw325 is offline
325ic E36 '94
Location: Los Angeles
 
Join Date: Nov 2011
Posts: 189
Mein Auto: BMW 325ic E36 1994
I know it's been a while, but was this resolved? And if so, what was it?
Reply With Quote
  #9  
Old 12-16-2011, 02:22 PM
smolck's Avatar
smolck smolck is online now
ROLL TIDE!
Location: Birmingham, AL
 
Join Date: Jul 2007
Posts: 22,348
Mein Auto: 2004 ZHP Sedan
Quote:
Originally Posted by jshough View Post
My local shade-tree completed the work for $300 which is also reasonable.

Good luck.
Sorry bud, but $300 for a Guibo replacement isn't reasonable. You got hammered.
__________________

Check out my YouTube Channel for DIY's and other fun stuff HERE
Check out my BMWBLOG!
Quote:
Originally Posted by Fast Bob View Post
now, go burn your Man Card, and buy yourself a Camry....
Reply With Quote
Reply

Bookmarks

Tags
e46, knocking, m3, noise


Forum Navigation
Go Back   Bimmerfest - BMW Forums > BMW Model Discussions > 3 Series / 4 Series > E46 (1999 - 2006)
Today's Posts Search
Thread Tools
Display Modes

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 On



Forum Jump


All times are GMT -7. The time now is 05:48 PM.


Powered by vBulletin® Version 3.8.7
Copyright ©2000 - 2014, vBulletin Solutions, Inc.
© 2001-2011 performanceIX, Inc. All Rights Reserved .: guidelines .:. privacy .:. terms