Wrangler 4WD L4-150 2.5L VIN P MFI (1998)
Valve: Service and Repair
Refacing Valves and Valve Seats
Clean all carbon deposits from the combustion chambers, valve ports, valve stems, valve stem guides and head.
Clean all grime and gasket material from the engine cylinder head machined gasket surface.
Inspect for cracks in the combustion chambers and valve ports.
Inspect for cracks on the exhaust seat.
Inspect for cracks in the gasket surface at each coolant passage.
Inspect valves for burned, cracked or warped heads.
Inspect for scuffed or bent valve stems.
Replace valves displaying any damage.
VALVE REFACING
1. Use a valve refacing machine to reface the intake and exhaust valves to the specified angle.
Valve Facing Margin
2. After refacing, a margin of at least 0.787 mm (0.031 in.) must remain. If the margin is less than 0.787 mm (0.031 in.), the valve must be replaced.
VALVE SEAT REFACING
1. Install a pilot of the correct size in the valve guide bore. Reface the valve seat to the specified angle with a good dressing stone. Remove only
enough metal to provide a smooth finish.
2. Use tapered stones to obtain the specified seat width when required.
