OEM 2001 Jeep Grand Cherokee Exhaust Valve

2001 Jeep Grand Cherokee Exhaust Valve Parts and Q&A

• Q: How to Service and Repair Exhaust Valve and Intake Valves on 2001 Jeep Grand Cherokee?

  A: The first part of servicing the valve is cleaning carbon deposits from the combustion chambers, valve ports, valve stems, valve stem guides and head. Calibrate the intake and exhaust valve angles with the machine so a margin of at least 0.787 mm (0.031 inch) results; if the margin is narrower, change the valve. When refacing valve seats, place a pilot of the recommended diameter onto the valve guide and grind the seat to the required angle using a dressing stone, removing just the necessary amount of material. Use rounded stones whenever the seat width must be exact and ensure valve seat runout is not more than 0.0635 mm (0.0025 inch). Remove the valve from the head and, using solvent and a bristle brush, clean the inside of the valve stem guide bore. Measure the space between the valve spring side of the head and the telescoping gauge which is inserted into the valve stem guide bore approximately 9.525 mm (0.375 inch) away. Measure the contacts on both sides of the cylinder head and seeing if the crosswise and lengthwise readings differ by more than 0.0635 mm (0.0025 inch); if so, ream the guide bore for an oversize valve stem. If the detected valve guide bore diameter varies from the specified 7.95 - 7.97 mm or 0.313 - 0.314 inches by more than 0.076 mm (0.003 inch), ream the housing bore for a valve stem that is slightly larger than the old one. A dial indicator is an alternative to measure the valve stem movement with the valve installed in its guide and just off the seat. The correct clearance is from 0.025 to 0.0762 mm or 0.001 to 0.003 inch. If the movement exceeds this, ream the valve guide to fit an oversize valve stem. Grounding the valve seats is important after reaming to make sure everything is straight with the valve guide.