I got a little problem with the A/C. I replaced a timing belt and water pump 3k miles ago, and the drive belts looked to be Ok at the time. I did get a little coolant on the A/C belt while replacing the water pump. When I took it down the road the belt starting squealing at about 5k rpm with the a/c on (t was quite with it off) I tightened up and it was fine for about 2k miles. I was in a traffic jam not running the a/c and had the bottom bolt on the tensioner snap.

Today I put a new bolt on the tensioner, and put on a new belt. I set the tension with about 3/16" of play. Now I get the squeal at around 4.5k rpm. when I cruise around town it does fine, but as soon as I hit the autobahn it will squeal for a second then it wont do it again for about 15-20 seconds. I can also feel the engine surge. I am thinking that the compressor is locking up. That is the only thing that I can think of that would cause the bolt on the tensioner to snap.