Ac Thumping Clicking Knocking - Please Make It Stop

[LukeG]

I've done a ton of searching on here and Google and haven't been able to find anything on this problem even though from what I am told it is pretty common. I added a few words I was searching for in the title just to make it easier for anyone looking for info on this problem to find the thread.

The car is a 94 LS400 and the AC is making a knocking/thumping sound. The colder I make the AC, the worse it gets (faster thumping). I can get it to go away if I make the AC pretty warm or I turn it off, but it is hot as hell here and I need the cold AC. A friend said it was some sort of actuator causing the noise and I've heard they are pretty pricey to replace because of the labor involved.

I was hoping to get a bit more info if anyone is familiar with this problem and at least get a better idea of what parts need to be replaced and how much of a pain in the butt it is to do. The repetitive thumping is going to drive me crazy.

Any help is greatly appreciated.

[Blayd]

When my AC got noisy it was because the compressor was worn out and I had to get a new one. $300 total fixed the problem for me. about $200 for a used comp off of ebay and about $100 to have it installed.