Sharan 1.9 TDI - Auxiliary Belt Flapping

[Knob Jockey]

1st post so go easy on me.

I've got a 1998 Sharan diesel and there's a noise when it's ticking over that's been getting worse over the past few months.

When I opened the bonnet today I found that the auxiliary belt is flapping about, if I rev the engine it's fine, it's just when ticking over. The other V belt is fine.

Any ideas, it's driving me :aargh4:

Thanks, KJ

[kenney]

check the tensioning element for the belt if it is ok then the alternator pulley wheel needs replacing

[Knob Jockey]

Thank you Kenney

I've just had a look at the plastic tension wheel, no cracks or lumps in it, but the alternator pulley looks ok too?

[kenney]

You can not tell by just looking at the wheel,you will need to remove the belt and test the one way function of the pulley

[Knob Jockey]

Ok, belt is off now.

If I carefully lock alternator the pulley won't turn either way, is this definitely a one way pulley?

[Knob Jockey]

So how can I tell if this is a free wheeling pulley?

[Knob Jockey]

No one way pulley on this, new belt fixed it:D