Test Procedure
WARNING: This page is about a different car, the 2009 GMC Sierra, 2009 GMC Cab & Chassis Sierra, 2009 Chevrolet Silverado, and 2009 Chevrolet Cab & Chassis Silverado. However, it is still accessible from the selected car via links, so may be relevant.
- Disconnect the battery ground negative cable.
- Remove the spark plugs. Refer to Spark Plug Replacement .
- Rotate the crankshaft to place the piston in the cylinder being tested at top dead center (TDC) of the compression stroke.
- Install the J 35667-A: tester, or equivalent.
- Apply shop air pressure to the J 35667-A: tester and adjust according to the manufacturers instructions.
- Record the cylinder leakage value. Cylinder leakage that exceeds 25 percent is considered excessive and may require component service. In excessive leakage situations, inspect for the following conditions:
- Air leakage noise at the throttle body or air inlet hose that may indicate a worn or burnt intake valve or a broken valve spring.
- Air leakage noise at the exhaust system tailpipe that may indicate a worn or burnt exhaust valve or a broken valve spring.
- Air leakage noise from the crankcase, oil level indicator tube, or oil fill tube that may indicate worn piston rings, a damaged piston, a worn or scored cylinder bore, a damaged engine block or a damaged cylinder head.
- Air bubbles in the cooling system may indicate a damaged cylinder head or a damaged cylinder head gasket.
- Perform the leakage test on the remaining cylinders and record the values.
WARNING:
Refer to Battery Disconnect Warning
.
NOTE:
It may be necessary to hold the crankshaft balancer bolt to prevent the crankshaft from rotating.