vibration

[jlars]

I was in town yesterday, stopped at a stop light and noticed a vibration from engine. a little bit later I was stopped and heard noise that sounded like a washing machine (along with the vibration) coming from engine compartment. Any ideas? 2001 Duramax 70,000 miles.......thanks

[jlars]

I found out what it was. It is the belt tensioner in front of engine. The belt seems to have more tension on it when air conditioner compressor is running(that is when it happens). It must have bad bearing or ?