Growling noise after A/C reservice

doerrd · Post by **doerrd** » 13 Jul 2013, 15:55

Hello,
Looking for some direction . . . I re-serviced my air-conditioning system today using the low pressure port. Now, I hear a loud distinct "growling noise" coming from under the hood associated with, what I think is, the cycling on and off of the compressor. The a/c is blowing cold and I did not overcharge the system. Does anyone have any idea what the cause of the growling noise could be?

Dave - 2003 XC70 - original owner

Post by **jimmy57** » 13 Jul 2013, 16:10

If you speed up the engine a little does the growl go away?
How do you know it is not overcharged?

P2's can have a growling noise when compressor comes on but I wouldn't describe it as loud and it diminishes after a bit.

doerrd · Post by **doerrd** » 13 Jul 2013, 16:20

Hello jimmy57, the growl comes and goes wether at speed or at idle, this noise is definately not the normal sound made with the compressor cycle. I used a pressure gauge when I reserviced the system and charged it appropriately with the ambient temperature outside. Do you think I may have unknowingly overcharged the system?

Post by **abscate** » 13 Jul 2013, 17:35

You need to charge to correct level at ambient temperature after equilibrating the AC system for 15 minutes with the engine running the compressor at rated capacity or above, which means >1500 engine rpm

Growling like a contented cheetah can be monitored to see if it is getting worse..if you hear snaps and thunks, the compressor replacement is beckoning...

doerrd · Post by **doerrd** » 14 Jul 2013, 07:50

Fixed! I think. That was the key = allowing the car to run for 15 min which I failed to do the first time. The system was overcharged and is now properly charged. The compressor is cycling properly and the "growl" has gone away. Thank you both for your help and advice.

Dave.