SOLUTIONS TO CHIRPBELT CHIRP: A sharp, high-pitched, repetitive noise of short duration, usually worse at low engine speeds (idle). As belt speed increases, the belt noise may blend into one audible noise, but most likely will diminish in intensity such that it won’t be detected. Most chirp noises occur as a short belt span enters into a grooved pulley, typically after exiting a backside pulley.
Possible Causes
• Pulley misalignment (axial and angular) …MOST COMMON
• Mis-installation
• Belt ribs extremely worn
• Worn pulley bearings (causing pulley wobble/excessive free-rock)
• Fluid contamination (Oil, P/S fluid, antifreeze, belt dressing, brake cleaner, etc…)
Possible Solutions
• Check alignment of all pulleys, either with a straight edge or laser alignment device.
• Insure all accessory pulleys and brackets are tightened snug to mounting surfaces.
• Upon belt installation, make sure the belt ribs are seated properly in all accessory pulleys. (It is not uncommon to install a belt one rib off onto a pulley flange).
• Since an existing misalignment condition will cause pre-mature wear of the belt ribs, a new belt is recommended once the accessory drive has been realigned.
• Inspect and replace all accessories/pulleys that are difficult to rotate (ie. Rough/seized bearings), or show excessive wobble/free rock.
• An accessory pulley that is difficult to insure good alignment is the P/S Pulley, since it is not mounted to a hard stop. This pulley is a common cause for belt misalignment.
• If at anytime the belt is contaminated with common engine fluids (as mentioned in #5 – Possible Causes), the belt should be replaced with a new one. |