VW PD 130 Noise & Jumping Aux Belt - Tensioner ?

[V8RX7]

Mate's Passat TDi PD130 - has an intermittant noise at the front with a vibration you can feel through the steering wheel.

When the noise occurs the aux belt jumps and the tensioner vibrates.

My question is:

Is it likely to be the tensioner failing (120k) or is it likely a PAS (or other) issue causing the tensioner to jump ?

If I push on the belt above the PAS pump it isn't as tensioned as I'd expect - equally I'm an old car guy so maybe that's as tight as it should be.

The Aux belt doesn't look that old, no history of the tensioner being changed.

[Mr-captain]

I have seen this on PD engines when the alternator pulley seizes.

[Belle427]

I'd agree with the above, I've changed one on the father in laws car and it made a big difference. Google alternator clutch pulley and it will give you an explanation, you do need the special tool to remove it.

[Polome]

Your alternator drive pulley clutch is on the way out. The pulley doesn't run freely and it's fluctuating speed causes drive belt slippage . This vairies power steering output pressure giving steering vibration. The pulley/ clutch unit needs changing asap before it breaks belt etc. a common fault and not hugely expensive fix.

Edited by Polome on Thursday 26th May 22:13