Is it a fan belt is it a water pump is it an alternator?

[rolesyboy]

For as long as I can recall my Mini makes a high pitched bark ? whenever I start it after it's been resting. Generally clears once been running for a while. How do I decipher which of the 3 it is. Fan belt has bit more deflection than I would like but can't get it any tighter. Cheers. Mark

[Spider]

Take the fan belt off and see if the noise goes away, then you've narrowed it down to that area.

Then, while running and making the noise, pour a little water on to the fan belt, if the noise then goes away, it'll be the belt.

I doubt the alternator would 'squeal' however the water pump may. I'd also suggest replacing the fan belt as if it's been doing it a while, it's likly glazed and so will slip very easily now. Also, have a good look at the Vs in the pulleys as these can wear too.

I'd have a guess and say that if it only does it for a short while after starting, it will be the belt slipping on the alternator pulley.

[cheleker]

Agree with Spider. A squirt of WD40 will also test the belt. The belt could be glazed or you have one that is wider than it should be.

[woodypup59]

Maybe the belt needs tightening.

Also check the in-plane alignment of all three pulleys.