Has anyone had a knocking noise when running your AC? I have a 99 4runner and when I switch on the AC there is a knocking noise. Any ideas?

thanks for any input!

 

Your compressor is on the way out.. Might try an oil charge.

 

My thoughts exactly! Probably not going to be very cheap unless you ca nget a used compressor and charge it yourself (depending on what refrigerant you are running) What year veh. do you own?

At least this didnt happen at the beginning of summer.


Welcome to the board!

 

i just hear like a churning.. like the engine is a little noisier or something.

is that normal, or do i need to do something about it as well?

 

Guys, he might be saying that he gets one knock sound when the clutch is engaged, which is what all (3) of my 4Runners and Tacoma did.

Now if it is a timed knock, then it's a different story. Please clarify.

 

99 4runner 60,000 miles. It's a consistant knocking, but speratic. It's not that loud, youcan turn up the radio and not hear it. Ac is pumping very strong.