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Valve Guide Measurement Procedure

WARNING: This page is about a different car, the 2002 Oldsmobile Aurora and 2001 Oldsmobile Aurora. However, it is still accessible from the selected car via links, so may be relevant.
  1. Measure the valve stem (1)-to-guide (2) clearance as follows:
    • Excessive valve stem-to-guide clearance may cause an excessive oil consumption and may also case a valve to break. Insufficient clearance will result in noisy and sticky functioning of the valve and will disturb the engine assembly smoothness.
    • Clamp the J 8001  to the cylinder head at the camshaft cover rail.
    • Locate the dial indicator so that the movement of the valve stem from side to side, crossways to the cylinder head, will cause a direct movement of the indicator stem.

      The dial indicator stem must contact the side of the valve stem just above the valve guide.

    • Drop the valve head about 1.6 mm (0.0064 in) off the valve seat.
    • Use light pressure when moving the valve stem from side to side in order to obtain a clearance reading.
    Fig 1: Measuring Valve Stem-To-Guide Clearance
    G01815883Courtesy of GENERAL MOTORS CORP.
  2. If the clearance for the intake valve is greater than 0.11 mm (0.0045 in) and a new standard diameter valve stem will not bring the clearance within specifications, the cylinder head must be replaced.
  3. If the clearance for the exhaust valve is greater than 0.12 mm (0.005 in) and a new standard diameter valve stem will not bring the clearance within specifications, the cylinder head must be replaced.
  4. Valve guide wear at the bottom 10 mm (0.39 in) of the valve guide is not significant to normal operation.
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