In some other Pittsburgh threads, others have recommended this shop and reported that the owner even drives a Jetta diesel. I can't vouch for this shop, however, as I've never used them:
Bobs Service.
518 River Rd
Dravosburg, PA 15034
412-469-9733
If you are new to the Pittsburgh area, Dravosburg is on the Mon River south of downtown. Go down Pa-51 and a little before you get to the Century III mall you take a left onto Pa-885 and it is probably 3 miles down the road.