I have a 2005 Grand Caravan w/ a 3.8 and have been experiencing belt chatter. At first I thought the problem was the water pump because I could see some wobble from the pulley, so I changed it. I noticed that after I changed the water pump that I could actually see the belt wobbling up and down when in gear, near the bottom pulleys. When I have the car in park the wobbling and chattering stops. My guess is that it's the belt tensioner but I wanted to get some feedback from people with more knowledge. Thanks in advance for any help with this problem.

 

By chatter you mean belt squeel or squeek?

 

Welcome to DF
Have you tried to see if the chatter is gone with the fan belt off?

 

I went ahead and replaced the belt tensioner and that seems to have fixed the problem. Thanks to those who responded.