I'm having some issues with the A/C compressor on start up. The A/C works fine except on start up usually all the time and worse on hotter days, the A/C compressor makes a loud rumble noise. It seems like the compressor is trying to seize up and slowing down the engine. This doesn't happen if I have the A/C off. I've tried putting in oil and refrigerant but it only went away for about 3 start ups. After a couple seconds the issue goes away and it runs fine. Its been like this for about 2 months. Anyone ever have this problem or know a solution?

 

Do you turn it straight to the highest setting on start up? Usually, you let the engine run on the lowest setting for a minute or two then you can turn it up. When I put my efan in my A/c sucked on start up. But now that I hooked it up to turn the efan on when the a/c is, it gets cool really fast. Compressors like to turn on and off in short pulses when running. You can hear it click on and off and the rpms noticeable drop then pick back up. If this sounds like what you are experiencing it is pretty normal when parked or sitting still.

But you did say "a loud rumble" and I'd be curious to know what that sounds like or really means...

 

yeah I usually have it on the lowest setting, then wait until it goes away to turn it up. I also can't drive the truck or rev it until it goes away, or it will get louder. I can't really describe the sound to well, its like when a large heavy metal object is dragged on the floor. If that even helps. My best guess is that the compressor is seizing up and fighting against the belt. also thins only happens when the truck has been sitting for more than maybe 30 min. I think I might just take it in to get it checked out.