When repairing engines with low compression due to leaking valves, it is not sufficient to reface or replace the valve seats and valves. It is also necessary to check the valve guides for signs of wear. This is especially important when checking high mileage engines.
Scheme 80
- Insert valve into guide until end of valve stem is flush with end of valve guide.
- Measure side-to-side play of valve. see scheme 89: Measuring Side-To-Side Play Of Valve (Valve-To-Guide Clearance) CAUTION: Due to differences in valve stem diameters, make sure that only intake valves are used to check intake guides, and only exhaust valves are used to check exhaust guides. SIDE-TO-SIDE PLAY OF VALVE - WEAR LIMIT Valve Wear limit Intake valve guide 1.0 mm (0.039 in.) Exhaust valve guide 1.3 mm (0.051 in.)