Cylinder Liner: Service and Repair

AH01.40-P-0001-03SM Notes For Evaluation Of A Cylinder Barrel

If condition of cylinder barrels cannot be assessed with sufficient certainty by means of visual inspection using an inspection light then the cylinder head must be removed.

The following information should be helpful in assessing the cylinder barrel and in making a correct decision concerning the condition and further use of a crankcase.

The following illustrated damage profiles are only an excerpt of possible forms of damage to the cylinder barrel. The surface quality of the piston and piston ring must always be taken into account in diagnosing the type of damage.

Normal condition







Matt gray surface, honing pattern visible, dry cylinder barrel, without oil residues, without polished places or reflective smooth areas. The cylinder barrels must not have any scorch streaks. Individual slight scores are not critical.

The honing pattern is more or less clearly recognizable over the cylinder barrel. The honing pattern may be partially worn away at the reversal point of the first piston ring.

The crankcase can be reused.

Carbon deposits on the cylinder barrel







Check top land unit of crankcase for carbon deposits (arrow).

In the case of carbon deposits (arrow) on the top land unit: clean top land unit and crankcase.

Individual continuous traces of scratches or score marks







Check area of contact surface in crankcase for traces of scratches (arrows).

The crankcase can be reused if there are light traces of scratches (arrows) or score marks on it.

Pressure gloss marks, smooth spots







Check at individual blank locations (arrow) e.g. in the middle of the cylinder barrel or an all-round impression on the piston ring reversal point above and below.

The crankcase be used again if there are isolated blank areas (arrow).

Piston seizure or roughened streaks, signs of seizure







The cylinder barrel is usually roughened over the whole length. Material deposits and perceptible seizure marks on cylinder barrel and also on piston skirt.

The crankcase is unusable and must be replaced.