Didnt get any action on this in the maint section, so trying here


LS2 Throwing AC BeltAC Belt new , tensioner new , normal driving all good, go nail it and ac belt pops off , sometimes even taking the main belt off. Any thoughts ?

Its a modded LQ9, AC in stock location. Even reordered a AC pro brand tensioner , same result. Engine winds up so fast Im sure its over powering the tensioner. I just dont know what the answer is to fixing this.

 

This was happening to my nephew. Built him a 6liter a couple years back. 02’ Silverado ext cab lowered on 20’s type of build. Pretty quick for what it is. Anyhoo, ended up that his A/C compressor was going bad. It worked and blew cold air, but at high rpm it would throw the belt and even took the main belt once. Replaced the compressor and all is well.

 

Take the belt off. Does pulley spin freely? Could be a too tight dust cover or clutch armature is to tight into housing.

 

Check your balancer make sure it is not wobbling off. Is it a stock balancer?

 

yes on stock balancer.. seems to be ok

I continued with the assumption that the engine was over powering the tensioner and causing the belt to jump off. So I fixed the tensioner so it had a good bit of pretension on the belt and locked it down like a fixed tensioner..

what happened next was unexpected. Cranked it up with AC off and at idle it appears to run fine. Rev it up a good bit . Quick shots , seems ok. At idle turn AC on and bad squeal. Best guess sounds like belt or compressor clutch , but its a metallic squeal. that starts and stops with compressor engagement. Drive it a little and belt pops off..

Oh yeah , one time it took the main belt out , that was a lot of fun.

 

Compressor clutch is slipping

 

64 dollar question , belt too tight or clutch going out ? with standard tensioner , no issue except throwing the belt LOL

 

Probably time for new compressor I had same thing happen expect in my case it just tore the belt up or threw it off the pulley when I turned ac on.