A/C Triggered Screeching noise

Last summer I changed all the belts on my 03 Tacoma 2.7... In the fall, I had this awful screech noise come from under my hood. It only triggers when my A/C is on and will last only a second or two before going back to a normal sounding taco.

I cannot get the noise to repeat or even happen while idling. That being said, I can drive around all day without the A/C and hear no screeching from underneath the hood. WHen I drive around with the A/C on, I will get sporadic screeching lasting only 1-3 seconds and then back to normal. My truck will slightly lurch and I mean slightly when the noise happens.

Is it a compressor issue, belt issue, or what? WHere do I start? Thanks.

 

Is the belt tensioned correctly? Might have broken in and need to be tightened

 

if belts are new , could be tensioner or worst case , compressor is on its way to a lock up

 

^^^^ What he said.

 

There's a squirrel trapped in your engine bay, you should probably let him out.

 

^^^^ Not what he said.

 

If it doesn't do it under idling conditions but is under load when I am in the middle of the gear does that detail which one it might be? Thanks.

 

And its very random... I can't pick up when it actually happens. I went 3 days with no screech and then it happened at the top of 2nd gear before I shifted to 3rd.

 

Any more thoughts?

 

Have you followed thru on any of the above advice?
If so, what have you learned?

 

I tightened up the ac tensioner today... Stay tuned

 

No screeching this far

 

Issue is resolved... thankful it was the ac unit.

 

If the A/C compressor was going, it would sound atrocious. Mine is going and it sounds like a cross between a diesel and a tea kettle.

It could just be the clutch bearing on the A/C pulley.

In case the screeching comes back.