99 LHS- A/C problem & Belt/pulley (?) problem

Last October I replaced both the ac/idler belt (which had snapped off), as well as the power steering/alternator belt. The air conditioner wasn't working, so this past summer I charged it with the stuff you can buy from the store, made sure the guage said the pressure in the system was fine, and all was well-- nice and cold. Shortly after that, when I had either the air conditioner or the heater or any other setting that moved air through the car on, at times when the car was idling, there would be an incredible initial screaching noise, which would stop when I accelerated. Once accelerating, though, there would be a noise that sounds something like a grinding, or a howling or something, coming from the general a/c pump area. Recently, the a/c belt snapped again, and so I replaced it again. A couple of questions: Does this a/c problem sound familiar to anyone? Any suggestions? Secondly, with both belts on and tightened to (I'm pretty sure they're good and tight) recommended tensions, there is still a loud and constant squealing noise (not as loud as the previously mentioned screaching) when the car is idling, or during light acceleration. When there is a harder acceleration or when its running at a higher RPM like highway driving, the sound dissipates and is gone. As I said, I'm pretty sure it's not the a/c or p/s belts, so what else could it be? Could this be related to the a/c problem or is it just an unfortunate coincidence? Any help would be greatly appreciated!

Did you find the problem yet? Did you replace the AC belt idler pulley? I had this grinding noise last year from my 2000 LHS when the engine was running. Went to the dealer, paid $35+ for diagnosis. I mentioned that I suspected the AC belt pulley. They came back saying there was nothing unusual about the sound of that engine!! They said it is a high output engine, thus the "rushing" sound!! Couldn't take the noise, which was not there before, any more, then bought an AC belt idler pulley for $17 from a local parts store. Replaced it myself in 15 minutes. It was a bad pulley bearing. The noise went away after replacing it. Should have gone back to the dealer to ask for the diagnostic fee back.

You may have a bad idler pulley bearing. If it binds up once in a while, it can snap the belt. It is cheap enough and easy enough to try. Here is how I find that to be the suspect. With the hood closed and engine running, stand on the right side (passenger side) of the car and listen. Then go to the left side and listen, if the pulley bearing is worn, the noise will be more pronounced on the passenger side. The pulley is located on the lower right front of the engine. You can replace it from underneath. I am sure you know where it is, since you replaced the snapped belt already. Loosen the tension adjust bolt, then remove the center bolt that holds the pulley. You can probably hear and feel the worn bearing when you remove the belt and spin the pulley, if it is the problem.

When you purchase the pulley, make sure they give you the correct one. Went to one store, they only carried the idler for the serpentine belt. The guy insisted that was the one, since the computer said so. It was not the pulley for the AC V belt. Didn't buy that. Went to the second store, they did the same thing, and then they look a bit harder, and found the correct one.

Good luck.

Norbe

That's great, thanks so much! Actually, I haven't gotten around to putting a new pulley on, but right now that's the last of my worries... the 99 LHS is literally falling apart right now... If its not one thing, it's another. I'm leaking oil and Power Steering Fluid big time, and the power steering is making a whining noise constantly. But, thanks for letting me know that a new pulley solved your problem! I'm definately going to try that!

could be the clutch in the a/c pump has bearings going also