Compression Check: Testing and Inspection
Compression Check1. Start and run vehicle until normal operating temperatures are reached.
2. Remove all spark plugs.
3. Disconnect coil leads.
4. Insert compression gauge into spark plug hole and turn engine over until compression stabilizes.
5. Pressure should read 150-177 psi.
6. If pressure is less than 150 psi, inspect valves and/or rings for damage, wear or not properly adjusted.
7. Low pressure in adjoining cylinders may indicate a faulty head gasket.