Check side clearance of piston rings

Check 

• Check the side clearance of the upper piston ring with a feeler gauge.
  TECHNICAL DATA - CLEARANCE OF UPPER PISTON RING SPECIFICATION
  
  

  Side clearance of upper piston ring
  Clean all components before measuring the side clearance.	0.07 mm... 0.11 mm

  Courtesy of BMW OF NORTH AMERICA, INC.

  Result 

  » Side clearance outside tolerance

  Measure

• Replace the piston rings.

  Check 

• Check the side clearance of the center piston ring with a feeler gauge.
  TECHNICAL DATA - CLEARANCE OF CENTER PISTON RING SPECIFICATION
  
  

  Side clearance of center piston ring
  Clean all components before measuring the side clearance.	0.07 mm... 0.11 mm

  Courtesy of BMW OF NORTH AMERICA, INC.

  Result 

  » Side clearance outside tolerance

  Measure

• Replace the piston rings.