A/C belt tensioner chattering
 

While on a short road trip last week the A/C belt tensioner started chattering, drove it that way all day got home and the next day I looked at the A/C belt and it was shot all weather cracked and worn. I have 114k miles on this thing so I installed a new serpentine belt and the a/c belt. The tensioner does not chatter like it did but you can hear it some times. I am hoping that its just the tensioner that's gone bad due to the bad belt and I can get away with just changing the tensioner. The other thing that worries me is that when we turn on the A/C the vehicle runs a little rough leading me to believe the compressor may be going bad and causing the chatter.... has anyone gotten away with just changing a tensioner and fixing this?

Anybody??

welcome to the forum,
What year is the vehicle?
the pulley most likely needs to be replaced,as for the poor idle when the AC is on the throttle body and throttle plate probably need to be cleaned of carbon build up...

Its a 2001 Suburban 1500 with a 5.3L Thanks. Yes I already cleaned the carbon because the throttle was sticking a little in the closed position i cleaned it as best as possible Including the throttle plate but I did not take the throttle plate off

Tensioner is not an uncommon failure. Easy to replace, but you have to get under the truck to replace it. 2 bolts and you are home free.

Yea I changed the tensioner and its still chattering I guess I'm changing a compressor next

I had an '01 Silverado 2500HD with the 8.1L and Alison 5 spd trans. My truck did the same thing and I replaced the tensioner as well turned out the clutch was going out in the A/C. Just make sure that if you are planning cleaning your throttle body that you take it off the truck to do so. I was cautioned by my local dealer mechanics that if the cleaner gets into the combustion chamber that it will react with the O2 sensors and the Catalitic converters.

while I was under the Suburban i turned the compressor and there was a steady resistance the clutch felt fine so I am ordering a compressor tonight (ouch) On the throttle body I just sprayed carb cleaner on a rag and wiped the inside of the throttle body till it was clean. I did not want that crud running into the cylinders.

keep in mind replacing the compressor is not always necessary the clutch assembly can be replaced if that is the cause of the chatter. replacing the clutch if its possible for the compressor you have will save you the trouble of opening the system

the chatter its coming from the belt tensioner bouncing up and down I can duplicate it by reving the eng a little while staring at the tensioner. how would the clutch cause this? could it be engaging and disengaging rapidly? the higher I turn the a/c up the worse it gets.