How to Repair a Whistling Noise

When driving a vehicle a slight amount of whistling is normal due to the airflow traveling over the body, windows and roof, but when sound levels increase it can tell you there is a problem.

What Goes Wrong?

Whistling noises can be generated by the engine, alternator or window and door seals that have an issue such as deteriorating rubber or corrosion on the battery cables forcing the alternator to overwork itself, or the alternator itself is going out.

What Does It Cost?

These kinds of repairs are two stages, first the source of the whistling sound must be located, followed by the repair of the problem. A shop or dealer will charge an hourly rate for both aspects of the repair.

Lets Jump In!

Vacuum is present when the engine is running and is at its strongest point when the engine is idling. This will generate various whistling noise pitches as the engine changes rotational speed. Lift the hood to inspect the engine vacuum line routing hoses to the different accessories such as the brake booster and EVAP system. Repair the vacuum leak as needed.
vacuum leak

The alternator is designed to recharge the battery and keep electrical power supplied to the vehicle when in operation. If the alternator is starting to go out or if it is being overworked by high resistance caused by dirty battery cables or a bad battery it can create whistling noise. To repair this issue start by cleaning the cables and checking the battery. If everything checks out, replace the alternator.
alternator whistle

When a door or window seal fails it can create a whistling noise as air enters and passes through the passenger compartment, it helps to have someone in the car with you to help find the origin of the noise, inspect the door or window seal in that area and replace or repair as needed.
door weather seal

A window seal has a top, bottom, front and rear sealing points, while traveling and the noise is being generated use your fingers against the seal to try and stop the noise this will let you know the location of the defect. In most cases the window seal will need to be replaced.
window seal

Windshields and sunroofs can also whistle when the seals have failed. Hood ornaments or other accessories on the exterior of the vehicle can whistle as well. We had a customer that change their antenna to one that had the mast bent into the shape of a horse, and it whistled. For window leaks a great trick is to turn the blower motor on high (non recirculation) and then go around the outside of the doors/windows with something like a smoke machine, incense stick or even a candle flame and watch for movement of the smoke or flame to show the leak location.


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