Autoelectro investigates the premature failure of the alternator clutch pulley and bearings, and starter motor burnout on a VW Tiguan.
Autoelectro’s experts have discovered that both the starter motor and alternator installed on the earlier Tiguans – 2008 to 2011, and 2011 to 2017 – have known faults, which can cause premature failures of the alternator clutch pulley and/or the bearings, as well as the starter motor.
Focusing on the alternator issue first, it is believed that the failure can be caused by contributing factors between the drive belt and drive belt components.
It is advised that all components within the drive belt system are inspected before fitting the replacement alternator (Autoelectro AEK2914), which can be achieved by the following:
- Ensure the belt is not stretched or damaged.
- Ensure the tensioner is operating correctly.
- Ensure all pulleys are functioning correctly
If any of the checks flag up any faults or suggest potential faults, the component must be replaced, as failing to do so will result in the premature failure of the alternator and may invalidate the warranty. To check that the clutch pulley is working as it should, the fan should be turning when the pulley is rotated.
In addition, the Tiguan has known faults which can cause the starter motor to burn out. The fault is often misdiagnosed as a faulty starter motor or solenoid. The following defects on the starter motor will give a strong indication of a vehicle fault that has caused the failure of the part:
■ Blue colour on the gear shaft and pinion area.
■ Rattling inside the starter motor when shaken, indicating components have exploded.
■ Burning smell from the starter motor, suggesting a varnish or insulation leak.
■ Damaged pinion teeth or a broken nose cone.
■ Burning, discoloured or melted broken wire from solenoid to starter body.
■ Shrivelled or burnt label.
If the starter motor shows any of the issues above, then a vehicle fault needs investigating, diagnosing and rectifying before fitting the replacement part (Autoelectro AEY2174).