A/C Noise

toyotadan04 · #1 (**permalink**) 06-10-2007, 10:44 AM

I have a wierd loud noise that is very abnormal when I first turn the A?C on after it has not been on for a while. It is a loud grinding/clunking sound with severe loss of power right when I press the button for A/C.

This sound only happens when it is the first time in the day I turn the A/C on. After that, only the normal sound when the A/C clutch is working. To me it sounds like unlubricated bearings grinding but I'm not too familiar with an A/C clutch set up.

Anyone else have similar experiences? If so, what have you done about it?

Splicer · #2 (**permalink**) 06-10-2007, 11:13 AM

It's pretty common, and mine does it... it's annoying as hell, but apparently does no harm. No cure that I've heard of.

flyman767 · #3 (**permalink**) 06-10-2007, 02:47 PM

Don't hear a peep out of mine; however, from what I understand this is caused by 'coolant lock' or similar known as 'hydraulic lock'. This is where the there are shallow 'air gaps' in the refrigerant lines and it's these air gaps that your hearing passing through the compressor mostly upon initial compressor start-up. More prevalent when the vehicle is cold. The dealer can add small amounts of refrigerant to try to eliminate these 'air gaps'... however, too much refrigerant can cause more system damage than not having enough. It's my understanding these small amounts of 'air gaps' passing through will not cause any premature wear of the compressor or related parts but rather just an embarrassing and annoying 'clacking' noise.

toyotadan04 · #4 (**permalink**) 06-17-2007, 09:02 PM

Thanks for the information! I won't worry about it, then.