How To Diagnose a Noisy Chattering VW Over Running Alternator Pulley

Do you hear a flapping chattering noise coming from the VW serpentine belt (aka VW accessory belt) area? Blauparts' video illustrates some of the flap and chatter noises associated with a bad VW over-running alternator pulley. The most common culprit for this noise is a failing VW over-running alternator pulley. Also known as a, VW ADP pulley, VW decoupler pulley, VW alternator freewheel clutch pulley, depending on the manufacturer.

A failing VW over-running alternator pulley can be easily misdiagnosed. After hearing belt noises coming from their VW accessory belt area and upon visual inspection, many notice excessive VW belt flapping and excessive tensioner vibration. We've seen many who have their accessory belt and tensioner replaced -- thinking the VW belt has a broken cord or that the VW tensioner spring was weak. But actually, the VW over-running alternator was beginning to fail and was the cause of their VW's accessory belt system problem.

See Our Related Video on How to Replace a VW Over-Running Alternator Pulley:    • How To Change or Replace the VW Over-...  

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Vw Beetle Over-Running Alternator Pulley - 1998-08 w/ 1.9L 4 Cylinder Diesel Engine
Vw Eos Over-Running Alternator Pulley - 2007-08 w/ 3.2L 6 Cylinder Engine
Vw Eos Over-Running Alternator Pulley - 2007-09 w/ 2.0L 4 Cylinder Turbocharged Engine
Vw Golf Over-Running Alternator Pulley - IV 1999-06 w/ 1.9L 4 Cylinder Diesel Engine
Vw Golf Over-Running Alternator Pulley - IV 1999-06 w/ Gasoline Engines and 120 Amp Alternator
Vw Golf Over-Running Alternator Pulley - V 2006-08 w/ 2.0L 4 Cylinder Turbocharged Engine
Vw Golf Over-Running Alternator Pulley - VI 2010-12 w/ 2.0L 4 Cylinder Diesel Engine
Vw Jetta Over-Running Alternator Pulley - IV 1999-05 w/ 1.9L 4 Cylinder Diesel Engine
Vw Jetta Over-Running Alternator Pulley - IV 1999-05 w/ Gasoline Engines and 120 Amp Alternator
Vw Jetta Over-Running Alternator Pulley - V 2006-08 w/ 2.0L 4 Cylinder Turbocharged Engine
Vw Jetta Over-Running Alternator Pulley - V 2006-10 w/ 1.9L and 2.0L 4 Cylinder Diesel Engine
Vw Jetta Over-Running Alternator Pulley - VI 2010-12 w/ 2.0L 4 Cylinder Diesel Engine
Vw Passat Over-Running Alternator Pulley - 2006-07 w/ 3.6L 6 Cylinder Turbocharged Engine
Vw Passat Over-Running Alternator Pulley - 2006-08 w/ 2.0L 4 Cylinder Turbocharged Engine
Vw Passat Over-Running Alternator Pulley - 2012-12 w/ 2.0L 4 Cylinder Diesel Engine