AC System converted from R12, now insanely loud compressor
 

Hey folks..

So the other day I had my AC system converted from R12 and recharged... The car had finally leaked out so much freon that the compressor was always engaging on/off and not cooling properly anymore..

So i get the car back home and run the AC with the hood open to let her run and simply look around. (I also had my MSD 6AL box installed while there) Almost instantly I hear a very fast and very loud ticking noise that wasn't there before.

http://i58.photobucket.com/albums/g2...h_IMG_0418.jpg

I took the car back to the mechanic today and tried to explain that it didn't do that before the system was charged.. To make a long story short he wouldn't take any responsibility and told me it was my fault for not servicing it sooner/it was a bad compressor... I won't be going back there anymore :mad:

Why would my compressor be doing this after a recharge?

Thx.

Re: AC System converted from R12, now insanely loud compressor
 

There are a couple things it could be.

Running the compressor when it's low on refrigerant is hard on the compressor for two reasons.
1) The constant cycling is hard on parts.
2) Running the compressor with too little refrigerant doesn't provide the cooling to the internal parts and slows the movement of oil through the system.

Switching from R-12 to R-134a means that the mineral oil gets removed and new PAG or POE oil gets put in. The trouble is that there will be chlorides in the system (in the pipes and hoses) that can never be removed. The chloride is the "C" in CFC that R-12 is........Not a problem in an R-12/mineral oil system. But the chloride doesn't mix well when PAG or POE oil gets mixed with it. This leads to acid and eventually takes out the compressor. But I wouldn't expect that to happen in one day.

The compressor is old and has probably served many years of long summers in Kentucky.

However, my guess is that when it got converted over, that the shop simply didn't put enough oil in the system. Get them (or any shop) to add another 1 oz of oil to the A/C system. This can be done without opening up anything or evacuating etc. There is a tool that looks like a tiny cylinder. You fill the cylinder with 1 oz. Close the lid on it. Then screw it onto the A/C service port and screw the oil into the system. This will probably take care of the noise you hear.

Re: AC System converted from R12, now insanely loud compressor
 

I installed a new compressor from Autozone as well as an Accumulator and an orifice tube. It was working fine for about half an hour and then the compressor locked up solid. I was told that they have a short shelf life and you can never tell how well it will hold up. Now I'm going have the original compressor rebuilt and put it back in. This way I will know for sure how long it has been sitting around.

Re: AC System converted from R12, now insanely loud compressor
 

My guess is a dry compressor from a bad conversion. Do you know what exactly the shop did? Was your system empty and inoperative for an extended period of time?

Off Topic....

IMO, the only way to convert from R12 to R134a is to:

1. Remove the evaporator and condenser and flush them.
2. Remove the hose assemblies and discard.
3. Remove the receiver/drier and discard.
4. Remove the compressor and keep it as a core.
5. Remove expansion tube and discard.
6. Flush the hard lines in-place.
7. Install new expansion tube.
8. Re-install the evaporator and condenser.
9. Fill a NEW compressor with ~75% of total system capacity R134a compatible oil and install.
10. Install new hose assemblies.
11. Fill the receiver/dryer with the remaining ~25% of R134a compatible oil and install.
12. Install the conversion gauge fittings.
13. Evacuate for at least an hour and make sure it holds vacuum for at least an hour (or longer)
13. Re-fill with R134a at 75%-80% of R12 capacity.
14. Fill out the conversion sticker and affix it somewhere under the hood.

I did my conversion to my '92 Lumina last year. It's a lot of labor but well worth the time and effort.