Valve Guide Inspection

GENERAL INFORMATION

When repairing a cylinder head with leaking valves, it is not sufficient to resurface or replace only the valves and seats. The valve guides must also be checked for wear. This inspection is especially important for engines with high mileage. Worn guides do not guarantee proper valve centering and cause high oil consumption. If wear is excessive, the valve guides must be replaced (performed at a workshop).

PROCEDURE

1. Remove the valve.

2. Clean the valve guide with a cylinder brush.

3. Insert the valve into the guide from the combustion chamber side and measure the clearance by moving the valve from side to side. Measure the valve clearance parallel to the corresponding rocker arm, because the greatest wear occurs in this direction.

4. To check, use a steel rule. There should be virtually no gap. Limit value: 0.2 mm.

5. If a micrometer and a bore gauge are available, measure the actual clearance between the guide and the valve stem.

6. If necessary, replace the guide (performed at a workshop).

Warning Never install a guide of the same diameter again. Valve guide / Specified value / Limit Intake 0.02 – 0.05 mm 0.10 mm Exhaust 0.04 – 0.07 mm 0.10 mm