Valve Guide Measurement Procedure
WARNING: This page is about a different car, the 2002 GMC Yukon XL, 2002 Chevrolet Suburban, and 2002 Chevrolet Avalanche. However, it is still accessible from the selected car via links, so may be relevant.
Important: Excessive valve stem-to-guide clearance may cause an excessive oil consumption and may also cause a valve to break. Insufficient clearance will result in noisy and sticky functioning of the valve and will disturb the engine assembly smoothness.
- Measure the valve stem-to-guide clearance.
- 1.1. Clamp the J 8001
on the exhaust port side of the cylinder head.
Important: The indicator stem must contract the side of the valve stem just above the valve guide.
- 1.2. Locate the indicator so that the movement of the valve stem from side to side, crosswise to the cylinder head, will cause a direct movement of the indicator stem.
- 1.3. Drop the valve head about 1.6 mm (0.064 in) off the valve seat.
- 1.4. Use light pressure when moving the valve stem from side to side in order to obtain a clearance reading. Refer to Engine Mechanical Specifications .
- 1.1. Clamp the J 8001
on the exhaust port side of the cylinder head.
- Valve guide (2) with excessive clearance must be repaired. Refer to Valve Guide Reaming/Valve and Seat Grinding .
- Replace the cylinder head if the valve guide cannot be repaired or reamed to accept an oversize valve stem.