Test Procedure
- Disconnect battery ground negative cable.
- Remove spark plugs.
- Rotate crankshaft to place piston in the cylinder being tested at Top Dead Center (TDC) of compression stroke.
- Install Cylinder Head Leakdown Tester (J 35667-A).
- Apply shop air pressure to the Cylinder Head Leakdown Tester and adjust according to the manufacturer's instructions. It may be necessary to hold the crankshaft balancer bolt to prevent engine from rotating.
- Record the cylinder leakage value. Cylinder leakage that exceeds 25 percent in considered excessive and may require component service. In excessive leakage situations, inspect for the following conditions:
- Air leakage sounds at the throttle body or air inlet hose that may indicate a worn or burnt intake valve or a broken valve spring.
- Air leakage sounds at the exhaust system tailpipe that may indicate a worn or burnt exhaust valve or a broken valve spring.
- Air leakage sounds 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.
NOTE:
It may be necessary to hold the crankshaft balancer bolt to prevent engine from rotating.