Quote:
Originally Posted by georgevan
This kind of problem has occured to us several times,with older BMW´s.
(150.000 kms about)
The problem is dirth collected on the rotor from the carbon brushes of the fan motor.
It is a small dark layer on the copper rotor.
After removing this discolouring,carefully,with very fine grinding paper,the squealing will be over.
(Seldom reason of squealing are bearings.I have never experienced this))
It needs a little more knowledge of engineering,to do this reparation.
And you must take your time....
The lifting out of the fan with motor will not be too difficult.(However..???)
The removal of the metal end cover of the electro motor must be done with the right amount of power. It is pressed in place by steel holders.
I use chisel and hammer,and pliers.Carefull,as mentioned...!!!
Than I take the coal brushes off the rotor,and with long strips of grinding paper (30 cm x 6 mm ),I clean the copper surface.
Surely dust has collected inside the motor,which can be removed with electro clean.
Reassemble parts,
(Push fan little in motor direction,otherwise coal brushes don´t reach rotor) and put steel cover plate in place.
Hammer steel holders,so cover plate stays firm in place.
I did this reparation several times,and only last time I was not sure,if operation succeeded,as I wanted,because the copper rotor was deeply scratched.
Am available,to provide further specific information.Fr.gr.George
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Thanks for the engineering insight
, but my 08 has about 14,000 miles on it, so I doubt the mileage has anything to do with this issue. At least in my case, it only happens when it's very cold, and most noticeable when slowing down on a slight left turn. After a warm up..no noise. It's hardly a wear and tear issue. I'm more than likely going to hold off till next winter, and see if it happens with the ac. It's just a small annoyance that I can live with..along with the peeling steering wheel..on a $60,000 auto.
..That I love anyway.
