Hey Everyone!

I have a 2011 Honda Civic LS 1.8L that just recently started rattling when the A/C compressor kicks in. The compressor was replaced a little over 6 months back and it cools great. It just recently started rattling, and only makes the noise when the compressor kicks in. The area of origin sounds like it's coming from near the serpentine belt but I don't see any obvious vibration aside from a bolt that is sticking out near the tensioner pulley (I believe that's what it is).

My first thought was a potentially bad bushing, until I realized it only makes the rattling when the A/C kicks in. See the attached pictures.

Any help would be appreciated!

Thanks,
Brandon

 

The ac kicking on puts some stress on the belt which puts stress on all the accessories that ride on it. It's likely going to be the tensioner pulley. You can replace just the pulley from Autozone for about $20. You will need to pull the belt and spin all those items to find the culprit. It will likely have noise. The tensioner pulley bolt is a torx t50 btw. Don't try using a 8mm allen on it. Torque it to 33 ft/lbs.

You need a new mount too. That one is done.

 

Mine did the same noise when the AC would click on. The tensioner shock absorber wears out. I couldnt loosen the Torx screw to replace the whole arm, but I was able to change the pulley and small shock absorber without a major problem. Noise is gone now.

 

if you feel vibration inside the car when the AC kicks in, then you mount need to replaced.