Radiator fan is aggressively loud when idling with A/C on

Every time my car is idling with A/C on (hot or cold), radiator fan kicks in suddenly and super loud, runs on high speeds for 10 seconds and abruptly stops. After 20 to 30 seconds of rest, it happens again, and again, and again…Possibly unrelated (or not) antifreeze level goes down super slowly. I took it to mechanics a few times. First, they did find a crack in antifreeze reservoir, got a new one, but problem was still there. Second time they fixed thermostat and expansion valve. Problem was still there. Check engine light came on, and the car started to have serious issues with slow driving, idling, it was shaking and acting really rough. New mechanic fixed manifold…that fixed the engine light thing. Radiator fan is still kicking in and off for very brief but super loud periods of time and antifreeze levels slowly go down. None of it is happening if I have A/C unit off…or driving. It just bothers me because the fan is extremely loud and I do not think it’s normal

Electric radiator fans run faster when the AC is turned on.

This is done so heat can be removed from the condenser and to prevent the engine from overheating.

If this car is new to you, what you’re hearing could be normal.

If this fan noise is new, then there may be a problem with the fan itself.

One thing to try is, open the hood with the engine cold, and try spinning the fan by hand.

If the fan doesn’t spin freely, the bushings/bearings in the fan motor are worn out and assembly requires replacement.



If you have had the vehicle a while and the fans seem ok as Tester pointed out then you could be low on freon and what you are hearing is the low pressure switch turning the AC compressor off (cycling) which in turn, turns the fans off… Or you could have a bad pressure switch… You would be better off having a certified AC tech hook AC manifold gauges up and check your AC system out…
What ever you do DON"T go adding freon to the system with out knowing the pressures 1st, too much freon can damage a perfect AC compressor/system…

With the AC off do the fans come on normal? If not it might be you’ve lost medium speed on your fan causing the car to get hot and have to go “jet” mode…

Cracked expansion tank? It happens. Bad thermostat? Same. Bad intake manifold gasket. Same. Odd running cooling fan? I’d sell it and buy a toyo or Honda. Don’t like trend here.