Checking the valve guides [Toyota Corolla E80]

When repairing a cylinder head with leaks in the valves, it is not enough to replace and mechanically treat the valve seats. It is also necessary to check the guide bushings for wear. It is especially necessary to conduct a complete check on engines that have been in operation for a long time. Wear of the guide bushings leads to incorrect centering of the valves in the seats and, as a result, to increased oil consumption. If the wear of the bushings increases, they must be replaced.

Remove the valve.

Clean the guide bushing.



Measure the inside diameter of the guide bushings at six points.



Measure the valve stem diameter at three points using a micrometer.

Subtract the average valve stem diameter from the average guide bush diameter. The result will be the maximum radial clearance.

Maximum permissible radial clearance:

• inlet valve 0.08 mm
• exhaust valve 0.1 mm

If the measured values exceed the permissible limits, the guide bushings must be replaced (work of a specialized workshop).