PRE-RELEASE
Cylinder Leakage Test
| Cylinder Leakage Test |
Special Tools
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EN-35667-A
Cylinder Head Leakdown Tester
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EN-39313
Spark Plug Port Air Adapter
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For equivalent regional tools, refer to Special Tools .
| Note | ||
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A leakage test may be performed in order to measure cylinder/combustion chamber leakage. High cylinder leakage may indicate one or more of the following: |
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Worn or burnt valves
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Broken valve springs
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Stuck valve lifters
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Incorrect valve lash/adjustment
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Damaged piston
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Worn piston rings
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Worn or scored cylinder bore
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Damaged cylinder head gasket
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Cracked or damaged cylinder head
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Cracked or damaged engine block
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Refer to Battery Disconnect Warning .
| 1. |
Disconnect the battery ground negative cable.
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| 2. |
Remove all spark plugs. Refer to
Spark Plug Replacement
.
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| 3. |
Rotate the crankshaft to place the piston in the cylinder being tested at top dead center (TDC) of the compression stroke.
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| 4. |
Thread the
EN-39313
adapter into the spark plug hole.
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| 5. |
Install the
EN-35667-A
tester or equivalent.
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| 6. |
Apply shop air pressure to the EN-35667-A tester and adjust according to the manufacturers instructions. |
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| 7. |
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:
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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.
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Air leakage sounds at the exhaust system tailpipe that may indicate a worn or burnt exhaust valve or a broken valve spring.
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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.
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Air bubbles in the cooling system may indicate a damaged cylinder head or a damaged cylinder head gasket.
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| 8. |
Perform the leakage test on the remaining cylinders and record the values.
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