AC making funny sounds

[rr080880]

Does this noise result in potential damage the compressor, or other A/C system component, or is it just irritating?

[racer2086]

I wish I could give you some advice, but that is the most vague post I've come across. What kind of noise? From where? Have a video? Year of your car? A/C service history?

[rr080880]

Sorry for vagueness. I was referring to the "whining" sound when A/C on, most noticeable at idle, as described in the previous posts to this thread. I have a 2001 740iL.

[acspecialists]

You may be hearing the refrigerant flashing in the evaporator. Most modern cars run the evaporator flooded to reduce superheat. If your charge is low you would be more likely to hear the liquid flashing to a gas.

[racer2086]

Is the whining the compressor "groan" that other posts talk about? Sometimes that is a factor of low oil charge or low refrigerant not providing enough oil to the compressor. If it goes right away when you press the snowflake button to turn off the compressor then that may be what you are hearing.

[serious7series]

so my A/C is no longer blowing cold air as of Dec. 2018. As you guys may remember form my post back in Nov. 2017 "Brought my 750 to a reputable indy AC shop. He first ran the AC at max and took the air temp coming out the main center face vents: 38 degrees F! He then tested the high and low pressure readings (both were within range @ 100psi and 28psi). He then added 1oz of oil to the AC system (PAG 100 is the correct oil, and the manual calls for a total of 6oz). Made no difference in that sound. He did not evac and refill, as he thought it wouldn't benefit anything. "

I need to bring it to a shop so they can diagnose it. Should I bring it to a BMW indy shop? or an A/C specialist indy shop? I know of 2 great shops of both kinds and have relationships with both.

[racer2086]

Either one if they do A/C work should be able to suck it down and charge it up. It's very straight forward with the right tools. Call and ask what an evac and recharge costs. Maybe that'll help make the decision.