ATTENTION: The manufacturer obliges car owners with a lot of wear on the camshaft and cylinder head bore to replace them without repair (grinding boring). But some specialized workshops have mastered the technology of repairing the camshaft, which consists in fusing the necks of the camshaft with metal, grinding the necks and boring the cylinder head hole to install the repaired camshaft.
The surfaces of the bearing journals of the camshaft camshafts should not show signs of wear, but small scratches on the cams can be removed with fine-grained sandpaper or a block. The surface of the cams must be well polished.
Measure the runout along the center journal by determining the maximum difference in the indicator reading per revolution.
The nominal runout should be no more than 0.02 mm, the maximum allowable runout is 0.1 mm. If the runout exceeds the allowable limit, replace the camshaft.
Measure the height of the camshaft cams with a micrometer.
The maximum allowable wear is 0.2 mm. If wear exceeds allowable values, replace the camshaft.