my buddy bought a 97 4.6 F-150 today with 128,000 on it. Runs perfect however the air compressor is making a really bad knocking sound when the air is off. A mechanic friend told me the compressor was bad. Is it possible that the bearing is bad, or the whole compressor? Does anyone have instructions/pictures of how we could go about replacing this ourselves?
I posted this in the HVAC board, but not a whole lot of people visit there, hopefully i can get more replies here. Thanks!


email is bigpat_98@hotmail.com

 

If the compressor is noisy with the A/C off, it could be a problem in the clutch assembly. Assuming the clutch isn't energized, nothing in the compressor is spinning. Does the clutch engage when the A/C is turned on?

 

Are you absolutely sure that it is the compressor? I thought mine was going out because of the same noise, ended up that the bearing in the belt tensioner pully was bad, cost about $30 to replace.

 

well we set it up to go in the shop on monday for the new clutch assembly. Going to cost around $190. I was wondering if perhaps the tensioner could be bad but oh well i guess we'll see what happenes. Hell, it aint my money....

 

I am having a similar problem.

When i have the A/C turned on there is a noise coming from the compressor area. It is gone when I turn off the compressor.

Would this seem to indicate the compressor or the clutch?

Thanks...