I’m sure somewhere there is a thread about this issue, however I can’t find anything on this issue, I have a 1999 civic ex coupe and when the ac is on and I accelerate moderately there is a noise almost like a belt squeal that happens but it goes away as soon and the ac clutch disengages, for example, when I drive the car lightly there is no noise but when I go to accelerate I can feel the acceleration get weaker when the clutch engages and go back to normal when it disengages, however if I apply moderate throttle *** soon as the ac clutch engages it squeals then goes away when it disengages or the car shifts gears or I let off the throttle,when the ac is off there id no squeal no matter how hard I press the throttle,same thing when I turn the ac button off but the vents still blow air there is no squeal, the ac compressor is new so I’m wondering if it’s a belt tension problem or maybe a bearing or pulley is having an issue, thank you for taking your time to read this and hopefully it’s not a super dumb question

 

Could be the AC belt is not tight enough. Could also be the AC clutch slipping. Did you also put a new belt on?

 

I didn’t replace the belt because it still appeared to be in good condition, I replaced the compressor condenser dryer and expansion valve and everything was working perfect until about a week ago then I started to have this problem

 

belt is likely too loose. But then again, it's only like $15. Just replace it.

 

The compressor ended up being the issue I had put a whole new ac system in the car but the ac lines we’re gunked up with this silver goop with metal shavings in it probably took out my new compressor so we ended ip flushing out all of the ac lines and put another new ac system in and it has been working perfect ever since