Valve Lash Adjustment: Notes

WARNING: This page is about a different car, the 2003 Pontiac Vibe. However, it is still accessible from the selected car via links, so may be relevant.

Tools Required

J 26900-13 Magnetic Indicator Base
J 8001 Dial Indicator Set
J 45785-1 Valve Spring Compressor

Important:

Valve clearance measurement should only be done on a cold engine.
To change the valve clearance on a given valve, the valve shim must be replaced by one that is thicker or thinner in size.
Valve shims are available in 41 different sizes, in increments of 0.020 mm (0.0008 in).
Valve shims range in size from 2.000 mm (0.0787 in) to 2.800 mm (0.1102 in).

Remove the cylinder head cover. Refer to Cylinder Head Cover Replacement .
Turn the crankshaft clockwise until the alignment notch on the crankshaft pulley is aligned with the "0" mark on the engine front cover tab.

Fig 1: Aligning Notch On Notch On Crankshaft Pulley
Courtesy of GENERAL MOTORS CORP.
Check that the point marks on the camshaft gears are aligned. If the point marks on the camshaft gears are not aligned, turn the crankshaft clockwise one revolution in order to align the camshaft gears.

Fig 2: Checking Point Marks On Camshaft Gears
Courtesy of GENERAL MOTORS CORP.
Using a feeler gage, measure the clearance between the intake valve shims and the intake camshaft for cylinders #1, and #2.

Fig 3: Measuring Clearance
Courtesy of GENERAL MOTORS CORP.

Intake Valve Clearance (Cold):

0.08-0.18 mm (0.0031-0.0071 in)

Important: Record any out of specification valve clearance measurements. The measurements will be used later to determine the required replacement shim.
Using a feeler gage, measure the clearance between the exhaust valve shims and the exhaust camshaft for cylinders #1, and #3.
Exhaust Valve Clearance (Cold):

0.22-0.32 mm (0.0087-0.0126 in)

Important: Record any out of specification valve clearance measurements. The measurements will be used later to determine the required replacement shim.
Turn the crankshaft clockwise 1 revolution until the alignment notch on the crankshaft pulley is aligned with the "0" mark on the engine front cover tab.
Using a feeler gage, measure the clearance between the intake valve shims and the intake camshaft for cylinders #3, and #4.

Fig 4: Measuring Clearance
Courtesy of GENERAL MOTORS CORP.

Intake Valve Clearance (Cold):

0.08-0.18 mm (0.0031-0.0071 in)

Important: Record any out of specification valve clearance measurements. The measurements will be used later to determine the required replacement shim.
Using a feeler gage, measure the clearance between the exhaust valve shims and the exhaust camshaft for cylinders #2, and #4.
Exhaust Valve Clearance (Cold):

0.22-0.32 mm (0.0087-0.0126 in)

Important: Record any out of specification valve clearance measurements. The measurements will be used later to determine the required replacement shim.
If there were any valve clearances that were out of specifications, the valve shims must be replaced.