Noise

DRIVE BELT NOISE/FLUTTER/CHIRP





Drive belt chirp occurs due to pulley misalignment or excessive pulley runout. It can also be the result of a damaged or misaligned pulley. Check each of the pulleys with a straightedge to the crankshaft pulley. Repair conditions in which any accessory pulley is out of position in the fore/aft direction or at an angle to the straightedge.

DRIVE BELT SQUEAL
Drive belt squeal is an intermittent noise that occurs when the drive belt slips on a pulley during certain conditions, such as engine start up, rapid engine acceleration, or A/C clutch engagement. Drive belt squeal can occur if:
1. The A/C discharge pressure exceeds specifications due to A/C system overcharge or A/C condenser core airflow blockage. Refer to Heating and Air Conditioning.
2. The A/C OFF equalized pressure (the common discharge and suction pressure that occurs after several minutes) exceeds specifications.
3. Any of the accessories do not rotate freely. All accessories should rotate freely with the drive belt removed: If not, inspect the accessory for damage or internal failure.
4. Fluid contaminates the drive belt. Contaminants include power steering fluid, engine coolant, engine oil or air conditioning system lubricant. If fluid contaminates the drive belt, clean the drive belt with soap and water then thoroughly rinse with clean water. The drive belt does not have to be replaced if no apparent damage has occurred.
5. The drive belt is too long. A drive belt that is too long will allow the drive belt tensioner arm (A) to go all the way to the arm travel stop (B) under certain load conditions, which will release tension to the drive belt. If the drive belt tensioner is resting on the arm travel stop, replace the drive belt (8620).
6. Remove the belt to avoid belt contact. Rotate the tensioner its full stroke to make sure there is no sticking or binding and to make sure spring tension exists.