Serpentine belt 06 jetta tdi

Very possible: bad alternator pulley clutch. Remove the serpentine belt and stick a soft wood stick to jam the alt fan. The pulley should only rotate 1 way. If it rotates 2 ways replace it. You need a special tool to loosen the pulley which can be purchased at metalnerd.com.

If not, bad tensioner?

Also, post moved to mk5 technical section, and title edited to add year.
welcometomyturbodies

I held the fan from moving the pulley did not move at all. Are all pulleys clutched?

No, just the alt pulley. Possibly a bad tensioner. Otherwise, is your crank pulley off? What service did it recently have that may have affected it?

Normally it's a weak tensioner.

fishon said:

I held the fan from moving the pulley did not move at all. Are all pulleys clutched?

Click to expand...

Are you saying the pulley only rotated in the correct direction? It could be a bad bearing in addition to a bad clutch.

I held the alternator fan from moving the pulley would not move in any direction. The tensioner has cracks in it. I am going to replace the tensioner and the pulley. Thanks

AH, ok, I misunderstood. Your alternator pulley is definitely bad than.

Take a look through your owner's manual and the 2005-2006 new buying checklist in the FAQ section for other stuff you may not be aware of.