I have a loud intermittent rattle coming from around the alternator when on tickover. I'm sure it's the alternator; there's nothing else in that area and the noise goes away completely if I remove the drive belt.
I've taken the alternator off, and the bearings seem fine. The only possible source I can find is a bit of end float in the alternator drive pulley. This pulley contains a device rather like a bicycle free wheel which (I suppose) lets the alternator keep on spinning when the engine slows down?

Is this a familiar problem? Could anything else be the cause?

Any help appreciated

 

It depends which model you have but many of the Audi's now use a free wheel clutch pulley made by INA. you should be able to learn more at http://www.ina.de/content.ina.de/en/...14/mot3414.jsp

you can also find more info and buy the products at smaller stores that carry the pulleys like www.americanenginesco.com or find them on ebay. (Schafler does not sell them to the public). Hope this is at all helpful.

 

Hi,
Thanks for the reply. This was a few months ago and is now solved. Truth is, I forgot to put the outcome on the forum.
The rattle was indeed caused by the freewheel clutch on the alternator. About £30 from a local motor factor and £5 to a local garage to swap them (I didn't have the tool to remove it from the alternator shaft) and it was all fixed.
I would have bought the tool, but thought I would never need it again...
Three weeks later, my Son (MK4 Golf diesel) started complaining of erratic power steering at low revs. When I looked under the bonnet the belt tensioner was shaking itself to bits! I removed the belt and found the alternator freewheel had siezed...
Cheers
Andy