Cylinder head bolts become thinner during operation. Whenever the difference between diameters "d1" and "d2" exceeds the maximum permissible value ("d1" - "d2": 0.15 mm) it is necessary to replace the bolts with new ones.
Note: If the minimum bolt diameter is outside the point "62" shown in the figure, measure it and take the value as "d2".
2. Deformation of the cylinder head surface:
Note: When performing this check, it is also necessary to check the cylinder block surface deformation.
Use a scraper to remove oil and water film from the surface (as inclusions), gasket, sealant, carbon deposits, etc.
Note: Be careful not to allow water or gasket particles to enter the lubrication passages.
Using a straightedge and a set of flat feeler gauges, measure the non-flatness of the cylinder head surface in six directions. If the results obtained exceed the maximum permissible value, it is necessary to replace the cylinder head with a new one.
A. Straight edge.
B. Set of flat feeler gauges.