E46 M3 Alternator noise\Whining

E36cab

Member
Hi guys, I'm in need of some help.

When I start my car up in the morning I hear a kind of whining noise from the alternator. This whining usually goes away after letting the car idle for 2-3 minutes or driving for about 1-2 kms.

Should i be concerned about this?
If so, does anyone know what could be wrong?

Thx fanatics!!!
 

frikkieh

///Member
Coismans car sounded like a vacuum cleaner, similar to what you describe.
He took it to an autoelec here in our neighborhood and got it reworked for a good price. The agents want somethimg like R4500 for a reworked part anyway.
Get him to an autoelec mate :thumbs:
 

E36cab

Member
frikkieh said:
Coismans car sounded like a vacuum cleaner, similar to what you describe.
He took it to an autoelec here in our neighborhood and got it reworked for a good price. The agents want somethimg like R4500 for a reworked part anyway.
Get him to an autoelec mate :thumbs:

Ok will do that. Mine is not as bad as a vacuum cleaner lol :=):
But I do get worried when i hear something unusual.
:ty::ty::ty: frikkieh
 

Peter@AEW

BMWFanatics Advertiser
Official Advertiser
It could possibly be a belt that needs replacing or more tension on it.

If it is a bearing in the alternator it will not stop the noise once "warmed up".

Check the tension on the belt
 

Dr Evil

Active member
my cart started whining in the morning, same thing, after a few minutes it would go away, i replaced both tensioner pulleys and belts and now the noise is gone

Sent from my HTC One X using Tapatalk 2
 

KSINGH

///Member
Usually the belt and tensioner pulley. But I have experienced that noise with the water pump as well. Replacement is the solution. Are you sure it's the alternator?
 

E36cab

Member
KSINGH said:
Usually the belt and tensioner pulley. But I have experienced that noise with the water pump as well. Replacement is the solution. Are you sure it's the alternator?

I've also replaced the 2 pulleys but whining is still there.
My mac say its there alternator and I should get a new\recon to replace.
Maybe as a1exander says, might need more tension :fencelook::fencelook:
 

P Smit

New member
If it is the alternator, replace it! Get a new one from the supplier, I think it is Diesel Electric. Had mine replaced last year at 84000km's.
 

Ram3on

Member
Take a long screw driver and at idle, place the tip as close as possible to the back of the alternators pulley and your ear against the back of the screw driver, if it is the bearing on the alternator it will make a serious noise through the shaft! Take care not to get the screw driver caught in the belt while you are performing this check!!! .....bearings on M alternators can be replaced :idea:
 

zaleonardz

Well-known member
my wife started whining in the morning as well, still have not found the cure.

Suggested we trade her in for a younger model, but the residual would have killed me..
 

E36cab

Member
Ram3on said:
Take a long screw driver and at idle, place the tip as close as possible to the back of the alternators pulley and your ear against the back of the screw driver, if it is the bearing on the alternator it will make a serious noise through the shaft! Take care not to get the screw driver caught in the belt while you are performing this check!!! .....bearings on M alternators can be replaced :idea:

Thx Ram3on, I tried the screw driver option and I do hear a noise but not sure if this is normal or not, the sound is not very loud.
I had the other tensioner pulley replaced today and the noise is still there on cold startup, so in total 3 pulleys were replaced.

I decided to leave this for a while, if it is the alternator bearing then it should get louder and be continuous.

Thx for the help guys!:thumbs:
 

E36cab

Member
Another question, can the bearing cease and cause the belt to slip off, or will there only be no charge from the alternator?
 
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