sabresfan

I just bought my daughter a 2006 Tc and I noticed while test driving it a rattle coming from the front end....only when moving, can hear it most when cruising about 30 mph over mild bumps. I asked the seller, who seemed to know a lot about cars and he mentioned it was a broken exhaust hanger-made total sense. The engine idles nice and quiet, smooth acceleration, tight steering and I had it in the air (before buying) and checked TRE, bearings, ball joints....all tight. After doing a little research I am terrified reading that a lot of people are mentioning the water pump?!?!?!? I am praying someone can ease my mind and tell me the exhaust hanger thing is common. The rattle almost sounds like a glass bottle rolling around....can anyone also be a little more specific describing the water pump issue? Are there signs or things I can check to see if I have a huge problem?

Many thanks!!!