A/C compressor noise??????

Sarge48 · **Joined:** Wed Sep 02, 2015 11:12 pm **Posts:** 18

My 06 CRD has a noise when the a/c is on that sounds like something is loose clanging and dinging around in there somewhere. I thought it was the compressor because it wasn't cooling real well either, so I had a new compressor put on and it still has that noise when the a/c is on. Any idea what it could be?

flash7210 · **Posted:** Mon Jul 04, 2016 9:38 pm

Check all your pulleys.
Is the belt tensioner bouncing around a lot?
It could be a bad alternator pulley or a bad belt tensioner.
The added load of the ac compressor makes the problem more noticable.

WWDiesel · **Posted:** Mon Jul 04, 2016 10:02 pm

Flash's advice is dead on,

first, make sure the alternator override pulley is functioning correctly!!! IT is is easy to test; remove the serpentine drive belt and manually spin the alternator in the normal belt rotation direction by hand and then grab the drive pulley and abruptly stop it, it should allow the alternator internals to still spin for a brief moment. IF it does not, you need to replace the alternator drive pulley with a new one...

second, watch the serpentine belt tensioner belt pulley, if it jumps up and down a bunch with a good alternator drive pulley at idle, then the spring tensioner has become weak and the whole assembly needs to be replaced...

and thirdly, I discovered this on my own CRD that it seemed to rattle at idle with the AC on more than it should even after replacing both items listed on 1 & 2 above...
I ordered and replaced both engine motor mounts and the rattle at idle was cured, GONE!!!! The motor mounts are hydraulic internally and can cause rattling issues especially at idle.... :shock:

The original drivers side motor mount after I removed it and shook it in my hand had an internal rattling sound....

Sarge48 · **Joined:** Wed Sep 02, 2015 11:12 pm **Posts:** 18

Thanks for the suggestions. I hooked up a freon canister to put more in it and the gauge went to red and according to the directions that indicates a problem. I will have a mechanic check the above items.

ebbnflow · **Posted:** Tue Jul 05, 2016 1:55 am

When my alternator decoupler first started to go bad, my serpentine belt would chirp only with the A/C on. As it got worse it would chirp all the time. If your A/C is working OK, I'd put my money on the alternator decoupler.

WWDiesel · **Posted:** Tue Jul 05, 2016 10:58 am

Another tip: there is a plastic cap on the front of the alternator decoupler pulley that can be easily popped off using a small screwdriver or pin punch type tool. Pop it off and if you find red dust under it (rust) it is a sign of a bad alternator decoupler pulley and should be replaced! :wink:

A/C compressor noise??????

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