If there are complaints for these vehicles that the engine will not start and/or misfires, a possible root cause may be the spark plugs. They should be checked and replaced if necessary. The vehicle manufacturer recommends the spark plug type:
- Spark plug type: FGR 8 KQE0
- Tightening torque 25 Nm
- Electrode gap 1.35 mm
A frequent cause of failure is short-range operation or frequent cold starts.
Fault patterns and possible causes (tightening torque too low):
- Thermal overload of the centre and/or earth electrode and/or the insulator base.
- A broken insulator base.
- A damaged thread.
· Thermal overload can be caused by not properly tightened spark plugs. Consequential damages, such as defects in the centre and/or earth electrode and/or the insulator base by loosening or vibration of the spark plugs.
Fault patterns and possible causes (tightening torque too high):
- The spark plug housing/insulator bond has loosened or been damaged. This caused the spark plug to become "leaky".
- Vibration has destroyed the spark plug completely.
- Excessive torque may cause violent rupture of the thread. (Heavy traces of the spark plug wrench may be visible on the hexagon.)
Consequential damages such as on the engine or cylinder head will not be accepted by the vehicle manufacturers due to various spark damages.
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