Cylinder Leakage Test

WARNING: Cylinder leakage checks must be performed with the vehicle in park or neutral and parking brake applied.

1. Start the engine and allow it to reach normal operating temperature.





2. Disconnect the ignition module connector.
3. Disconnect all spark plug wires and remove plugs.

NOTE: The piston must be located at exactly Top Dead Center (TDC) or the crankshaft will rotate when air pressure is applied.





4. Rotate the crankshaft so each cylinder to be checked is at TDC. Timing marks are located on the front cover and vibration damper assembly for TDC verification. Access to the front crankshaft damper bolt can be achieved from the top of the vehicle with an open end wrench. A 3.175 mm (1/8 inch) brass rod can be inserted through the spark plug hole to determine piston location relative to TDC.

NOTE: Air supply for the tester should be clean and free from oil, moisture and/or foreign particles that might be injected into the regulator or orifice chamber. Foreign debris can cause improper operation and erroneous readings.





5. Attach an air supply to the cylinder leakage tester. Desired regulator "In" minimum pressure is 861 kPa (125 psi), maximum is 1034 kPa (150 psi).
6. Insert the cylinder leakage adapter in the spark plug hole with the piston at TDC.
7. Close gate valve and adjust regulator pressure to 689 kPa (100 psi). Open gate valve. Observe the crankshaft during this operation.

CAUTION: If the crankshaft rotates, the piston was not at TDC. The crankshaft will have to be relocated at TDC.

a. Allow 60 seconds for the air pressure in the cylinder to stabilize. Observe the cylinder pressure gauge and record the pressure.

NOTE: Make sure all cylinder leakage adapter fittings are tight and the piston is at TDC or incorrect readings will be obtained. Check lower cylinders.





b. Listen for escaping air at the throttle body air inlet, oil fill cap, exhaust outlet.
c. Remove coolant bottle pressure cap and look for bubbles.
8. Repeat previous steps on other cylinders. Record the pressure.
^ Normal Cylinder Leakage: 10%-69 kPa (10 psi)
^ Maximum Leakage: 20%-138 kPa (20 psi)
^ Difference Between Cylinders: 5%-34 kPa (5 psi)
9. Remove cylinder leakage tester and install spark plugs. Torque: 27 Nm (20 ft. lbs.)





10. Connect spark wires. Make sure spark plug boots are firmly seated.
11. Connect ignition module harness plug.