Weird thing with AC

[leelee1981]

I have a 94 and when I'm driving about 55+ and have the a/c or heater on I hear this sweak sound like a mouse and the car jumps it only does it when the a/c is on I thought maybe the compressor belt was going bad or had some rough spots on it so i brought it in they said the belt was fine. Any Ideas?

[david103]

mine does the same thing, and i also have no clue what it is. someone help us!!! i thought it was my clutch deciding to slip randomly, but i doubt that, but it IS what it feels like...<P>dave

[Swego]

The thing is your a/c compressor is not working 100% of the time. When you turn it on a magnetic clutch on the a/c compressor engages and pumps pressure in the a/c system. When pressure is at a certain level the clutch disengages. It reengages again when pressure drops. If you're going 55mph the engine is reving pretty fast and the compressor is not, what you feel is the drag of the a/c compressor kicking in. The a/c compressor is belt driven, so as it kicks in, the belt might slip if it's not tight enough.

[leelee1981]

I guess your saying I need a new compressor? [img]shrug.gif"%20border="0[/img]

[Swego]

You probably need to tighten the belt that drives the compressor. I also used a special liquid that stops belt slipping. Some say that this is not good for the belt, but mine's still holding and the slipping is probably more damageable than this liquid.