Ever seen a grooved tensioner pulley?


Top Post Dawg
Aug 2, 2006
Newburgh, NY
04 Jetta GLS BEW, 14 Audi A7 V6 TDI, 13 Porsche Cayenne V6 TDI
I honestly forgot at first that the BEW with it's double sided grooved pulley still uses a smooth tensioner pulley but you can see why:

The AC compressor pulley bearing seized and overheated. The hot belt melted grooves in the pulley before breaking (threads are like screw threads so I'm sure it walked it right off). I thought the parts store had the wrong part stocked at first :)
I posted it in the 'check your fans' / ac troubleshooting thread, but here is the AC coil (was melted to the pulley):

The compressor still spins by hand - hopefully it wasn't damaged. Guess I'll find out once the new parts arrive.