Chirp Noise From Engine Compartment (Replace Accessory Drive Belt and Water Pump Pulley)

Some customers may comment on a chirp or noise coming from the engine compartment. Upon inspection, technicians may find that the noise is coming from the accessory drive belt that powers the water pump, power steering pump, alternator and other components.

Important: This is NOT the drive belt that powers the supercharger in supercharger-equipped vehicles.

This condition may be caused by a slight variation in the alignment of the accessory drive pulleys. When this variation occurs, it causes the accessory drive belt to shift slightly inwards or outwards.

Replace the accessory drive belt and water pump pulley on affected vehicles. The belt currently available from GMSPO is made of a material that best reduces any noise while maintaining durability. The new water pump pulley features a revised crown. The revised crown (the surface that the back side of the belt contacts) is flatter and allows the belt to align itself better based on any alignment variation.

Refer to the Engine Mechanical - 3.8L subsection of SI for accessory drive belt and water (coolant) pump pulley procedures.

For vehicle repaired under warranty, use: