02 Sierra 2500hd new ac belt tensioner vibrating bad when engine is re

[nickkastner]

I have an 02 GMC sierra 2500hd 6.0 that has problems with the ac belt tensioner or compressor. The belt is new and the tensioner is also new. The new tensioner took away the squealing but the violent rattlng of the tensioner still remains. It rattles bewtween 1000rpm and 2000rpm but i dont want to go any higher in fear of throwing a belt or busting the new tensioner. If you have any suggestions of what it could be, please reply. Oh and the belt doesnt make any noise when its idling of course.

 

Things is might be: compressor clutch?

low freeon pressure?

 

i dont know

 

Thanks

Nick

[davester]

What is the belt and/or tensioner doing? Is the belt flopping around a lot? Is the A/C compressor engaged when it happens or does it always happen regardless? Does the belt seem to have good tension with the engine off?