Tools Required
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.
J 35667-A Cylinder Head Leakdown Tester or equivalent. See Special Tools .
IMPORTANT:
A leakage test may be performed in order to measure cylinder/combustion chamber leakage. High leakage may indicate one or more of the following:
- Worn or burnt valves
- Broken valve springs
- Stuck valve lifters
- Incorrect valve lash/adjustment
- Damaged piston
- Worn piston rings
- Worn or scored cylinder bore
- Damaged cylinder head gasket
- Cracked or damaged cylinder head
- Cracked or damaged engine block
- 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 or equivalent. See Special Tools .
- Apply shop air pressure to the J 35667-A and adjust according to the manufacturers instructions. See Special Tools .
- 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 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.
CAUTION:
Before servicing any electrical component, the ignition and start switch must be in the OFF or LOCK position and all electrical loads must be OFF, unless instructed otherwise in these procedures. If a tool or equipment could easily come in contact with a live exposed electrical terminal, also disconnect the negative battery cable. Failure to follow these precautions may cause personal injury and/or damage to the vehicle or its components.
IMPORTANT:
It may be necessary to hold the crankshaft balancer bolt to prevent the engine from rotating.