Causes of idle-running performance

Unequal cylinder fill levels

• Eccentric shaft of the left and right cylinder banks do not work synchronously
  
• Unfavourable tolerance of the Valvetronic mechanism
  
• Wear in the Valvetronic mechanism
  
• Combustion chamber leak
  

Ignition problems

• Defective spark plugs
  
• Defective ignition coils
  

Fuel supply

• Defective fuel injectors
  

Body

• Tensions in the bracket of the drive train
  
• Defective engine mount