Replaced my A/C compressor along with accumulator and orifice tube. Flushed, vaccumed, and recharged with 3 12 oz. cans of R134a. Had a small problem with one of the o-rings causing a leak at the accumulator but quickly fixed that, re-vacuumed, and re-charged. A/C is working perfectly fine, blowing cold around 40-45*F. Only thing is when the compressor is engaged is sounds like its knocking, gets a little less noticeable as it warms up. Any one have any idea what this might be from? Low on pag oil maybe?

BTW, pressures were around 45 psi and 210-215 psi with ambient temps a little over 80*F.

Any insight would be awesome, the noise is driving me crazy after I spent all weekend on it!

 

Did you install the correct amount of the correct viscosity oil into the refurbished system?

Did you charge the correct weight of refrigerant (see underhood sticker) into the system?

 

The system called for 7 ounces of pag 46, and 2 lbs of r134a. I added 3 12 oz cans, assuming about 10-11 oz from each can actually made it into the system. As for the pag oil, the compressor came with 6 oz however when I spun the compressor before/ during install, some came out. I added about 3 oz to the original new accumulator because of this. When I discovered the o ring on that accumulator was bad and had to evacuate the system right after, I also assumed some oil was lost once again. I then added 2 more oz of pag 46 and vacuumed and recharged the system to where it is now. I've added 2 of those compressed cans of pag oil which have 1 oz of oil in them

Not sure if the compressor was bad right off the bat or what

 

Some are just a little noisy from my experience. I do 8oz of oil. 4 in compressor and 4 in receiver drier. After all the lines are hooked up I do 15-20 rotations of the compressor clutch (not pulley two separate things) then vacuum and recharge.

Where did you buy the kit from? If it gets louder I would warranty the compressor. Like I said some that I install are louder then others.

 

I ended up adding another 1 oz last night just to see, should put it right around 7-8 I assume. I got it from Advance Auto, it has a two year warranty on all of the parts so I'll probably just stick with it for now. I'm starting to think it may may just be a noisy compressor and I might have to dampen the sound if it bothers me that much, but it seems to have gotten a little quieter compared to how it was at first. I'll try to post a video of it later today for a better idea

 

Just an update incase something similar occurs with anyone else:

Decided to go back to the store and take advantage of the warranty. Upon removing the new orifice tube, it was completely caked with metal shavings, some of which were pretty large. I again had some troubles with the o-rings on the new accumulator leaking, but I replaced them and it is holding a vacuum just fine.

Lesson learned, your new AC compressor shouldn't sound like its about to blow up right out of the box.