Causes and Solutions of Car’s Humming Noise When Idling

A buzzing sound usually indicates a problem with the engine or another component

A buzzing sound usually indicates a problem with the engine or another component

A loose or missing drive belt could also be the cause when the engine is idling

A loose or missing drive belt could also be the cause when the engine is idling

It could also indicate a problem with other idlers used to keep the belt in place. 

It could also indicate a problem with other idlers used to keep the belt in place. 

Another type of "humming" noise can be produced when air leaks from the car.

Another type of "humming" noise can be produced when air leaks from the car.

To solve it, first we need to figure out what's making the buzzing sound

To solve it, first we need to figure out what's making the buzzing sound

The car is left running while we listen for the source of the noise with a stethoscope.

The car is left running while we listen for the source of the noise with a stethoscope.