Do you hear a chirping or squealing when you start your car? It could be the serpentine belt. Follow this guide to apply belt dressing to light or moderately squeaking belts.

There is some disagreement about whether or not to apply belt dressing to modern belts. In general, it is considered a short term fix and should not be used for very loud excessively squealing belts which can indicate a more serious problem such as misalignment of the belt wheels, a bad bearing, or a worn belt. In my experience, if there is a light chirp coming from the belt, a short squirt of belt dressing can make the belt slightly more pliable and eliminate the sound.

If this is your situation, read on for the procedure.




Pop the hood and prop it up. Start the vehicle and let it idle.

Caution: From here on, you will want to exercise caution! Do not get something caught (shirt sleeve, hair, fingers, etc.) in the belt, as this could be disastrous.

Locate the serpentine belt in the engine bay of your vehicle. For this Toyota Sienna, it is located to the left of the engine.


Here is a close up.


Take the belt dressing, and carefully spray some on the grooves of the belt. A few short shots will usually do it.

Caution: A fine mist of belt dressing may spray everywhere, so you might want to wear old clothes for this!


Usually the chirping will stop immediately. If it does not, or the squealing returns, it is likely indicative of a more serious condition, which should be investigated further.

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