Assessment of Cylinder Bores

NOTE: A visual inspection is to be carried out with a cylinder inspection lamp, the cylinder head being in situ. To do so, first remove the precombustion chambers. Service and Repair






Workshops often find it difficult to assess whether a scored or streaky cylinder liner is so seriously damaged that the engine needs removing or repairing or whether the marks are insignificant. The following notes are intended to help you make a correct, professional decision.

First examine cylinder liner marks to distinguish between "optical streaks" and "seizing marks". "Optical streaks" are normally up to 3 mm wide. They are due to the ring gap but still show signs of honing. In contrast, "seizing marks" make the honing traces disappear completely.

"Streaks at the land side" (in the direction of the piston pin) cannot be due to piston skirt slurring or seizing because there are no points of contact between the piston skirt and cylinder liner,