Hello,

As I was driving my '09 5MT w/ 125k miles a couple days ago I started hearing a very loud clacking noise coming from the engine bay at low RPM. It sounded exactly like piston slap, but when I used my redneck stethoscope (1 inch dowel) it seemed like the noise was coming from the A/C compressor. I just now yanked the serpentine belt and tried running it without the accessories connected, and sure enough the sound is gone. When I spin the compressor pulley it sounds like a box of rocks, has some in/out play, and grinds to a stop after a couple seconds.

The A/C has been ping ponging between very weak and completely nonexistent for the 5,000 miles that I've owned the car, and when I tried one of those Autozone recharge kits a couple weeks ago it showed a healthy 30 PSI. So, I am wondering whether I should bother just replacing the bearing, just replacing the clutch assembly, or go for the whole compressor unit altogether. I don't understand A/C systems well enough to know whether a bearing or clutch could cause failure of the system or make a sound that loud, but if there is a chance, I'd like to try that before replacing the OEM compressor with some Chinese re-manufactured garbage, or bypassing the thing entirely with a belt for a non-A/C equipped model.

Any input is appreciated, thanks for reading.

 

At 125,000 miles the AC compressor might be worn out. On my Civics I just replace the whole assembly (compressor and clutch). One gave out a 155,000 miles and the other stick shift one at 130,000 miles. Manual transmission cars are a bit harder on the AC compressor which might explain why yours went out at 125,000. Should be easy to get one at the local auto parts store. I heard some stores will even lend you a vacuum pump and manifold. Pump it down to at least 500 microns before recharging. You may also want to get a new A/C relay. They can be troublesome too.