Valve Rocker Arm and Shaft Cleaning and Inspection
WARNING: This page is about a different car, the 2007 Saturn Vue. However, it is still accessible from the selected car via links, so may be relevant.
- Inspect the rocker arm shafts (220, 221) for scoring or excessive wear.
- Measure the diameter of the rocker arm shafts.
- Measure the inside diameter of the rocker arm bores. Inspect for an out-of-round condition.
Specification: Rocker arm shaft bore diameter: 20.02-20.05 mm (0.788-0.789 in)
- Repeat the measurements for all rocker arms and shafts. Determine the shaft-to-rocker arm clearance. If the clearance exceeds the service limit, replace the shaft and all rocker arms with excessive clearance.
Specification:
- Intake rocker arm-to-shaft clearance - new: 0.026-0.067 mm (0.001-0.0026 in)
- Intake rocker arm-to-shaft clearance - service limit: 0.067 mm (0.0026 in)
- Exhaust rocker arm-to-shaft clearance - new: 0.026-0.077 mm (0.001-0.003 in)
- Exhaust rocker arm-to-shaft clearance - service limit: 0.077 mm (0.003 in)
- Inspect the intake rocker arm pistons (1). Push the pistons manually. If the pistons do not move smoothly within the bores, replace the rocker arms and pistons as an assembly.
- Inspect the locking nuts (217) and bolts (216) for damaged threads.
- Inspect for worn rollers (2), loose rollers or rollers with flat spots.