Q: Car is making a noise while idling. It sounds as though a motor bike is nearby. What might it be and is it safe? 2000 BMW 528

asked by on December 28, 2016

The noise starts after being still for a short time when at traffic lights or when stuck in traffic. When I first heard it I it was coming from a car in front.

My car has 145000 miles.
My car has a manual transmission.

Hello - the sound you hear is most likely the electric cooling fans coming on while the vehicle is stopped. The lack of airflow across the radiator while stopped or moving slowly causes engine temperature to rise, triggering the cooling fan switch and the fan to come on, cooling the engine back down. This cycle is automatic, and is a good thing!

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