B5,96,A4

recently my cooling fan is turning on while I'm driving and it sounds like a plane and it's about to take off the car is not overheating or nothing like that i just replaced tepm. sensor cuz my temp. gauge was acting-up.
any ideas anyone where should i start to fix the problem? it really bothers me

fjasper

This might be a failed fan speed controller or one of the electric fans might be dead, causing the other one to run on high to compensate.

I'd start by verifying which fan/fans are making the noise. If it's the engine-driven fan, it's probably the viscous clutch. A cracked/broken fan blade might make noise, too, I'm not sure. Some people have had lots of problems with the fans breaking.

If it's one of the electric fans running on high while the other one sits still, it's probably because the fan controller is trying to compensate for one dead electric fan. Troubleshoot the fan that's not turning.

If it's both electric fans, then it could be either the fan controller or one of the temp sensors. I think it's the one in the (lower) return hose from the radiator that switches the electric fans to high. Troubleshoot the switch first, it's cheaper.

B5,96,A4

Thank you
i'll start on that .....