Drive Belt: Testing and Inspection

NOTE: The following are symptomatic noises of the accessory drive belt system:

CHIRPING
- A high pitched noise that is usually heard once per revolution of a pulley or a belt.
- It is most common on cold, damp mornings.
- Verify this condition by squirting water onto the belt. The noise will momentarily stop.

SQUEAL
- A loud screeching noise that is caused by a slipping belt (this is unusual for a multiple ribbed belt).
- The noise occurs when a heavy load is applied to the belt, such as an air conditioning compressor engagement, snapping the throttle, or slipping on a seized pulley.

KNOCKING
- A low pitch tapping noise caused by belt misalignment.
- This noise occurs on cold start-up at idle.

WHINE
- A high pitched continuous noise that may be caused by a failed component bearing.

FAINT CYCLE RUMBLING
- A low frequency noise heard once per revolution of the belt.

PILING
- The random accumulation of rubber dust in the bottom of the multi-ribbed belt grooves.
- A small amount of piling is normal.
- Operation of the drive belt system will not be effected unless the buildup exceeds one third (1/3) of the belt groove depth.

NOTE: Multiple ribbed, accessory drive belts wear evenly with their pulleys. Unusual wear indicates a correction is needed.