Engine - Cylinder Wall Inspection: Overview
Date: May 19, 2009Order No.: S-B-01.00/27
Group: 01
SUBJECT:
MY-All, Models with Engines 112, 113, 137, 272, 273, 275
Cylinder Barrel Inspection
Cylinder Wall Inspection
If engine complaints regarding noises, overheating, or oil consumption arise, visually inspect the mounted cylinder head with a light probe and endoscope (bore scope). If visual inspection with an endoscope is not sufficient, consult the following documents in WIS: "Check compression pressure" and "Check cylinder leakage" before removing the cylinder head (WIS documents AR01.00-P-1300, AR01.00-P-0200, AR01.00-P-1200, AR01.40P9201AA, etc.).
When inspecting Silitec barrels with a light probe it is absolutely essential to observe all possible scenarios before removing an engine or replacing a crankcase. Section A describes acceptable cylinder barrel wear and section B describes the cases where cylinder barrels are deemed unacceptable and the crankcase should be replaced.
Ideal (Normal) Cylinder Wall Condition
The ideal is a matte gray surface, no honing pattern, and a dry cylinder barrel without polished sections or mirror polished flats. Individually assess any irregularities (Figure 1).
Note:
Do not replace crank case based on suspicions only. Perform checks and / or repairs according to published WIS, DTBs, and other official documents. If other than crankcase components are determined to be a cause of complaint, replace only affected components.
Note:
Use only approved methods to remove any carbon deposits when performing a repair. Do not use any sand paper, abrasive pads or disks or grinding and sanding tools. Use only approved fuel additives. Dealers might be debited when performing unapproved or incorrect repairs as well as when unnecessarily replacing parts.