Compression Check: Testing and Inspection
MEASUREMENT OF COMPRESSION PRESSURE1. Warm up engine.
2. Turn ignition switch OFF.
3. Release fuel pressure.
Refer to Powertrain Management; Fuel Delivery and Air Induction.
4. Remove all spark plugs.
5. Disconnect distributor coil harness connector.
Part 1 of 2
Part 2 of 2
6. Attach a compression tester to No. 1 cylinder.
7. Depress accelerator pedal fully to keep throttle valve wide open.
8. Crank engine and record highest gauge indication.
9. Repeat the measurement on each cylinder.
^ Always use a fully-charged battery to obtain specified engine speed.
Compression pressure: (kPa (kg/cm2, psi)/rpm)
Standard:
1,275 (13.0, 185)/300
Minimum:
1,079 (11.0, 156)/300
Difference limit between cylinders:
98 (1.0, 14)/300
10. If compression in one or more cylinders is low, pour a small amount of engine oil into cylinders through spark plug holes and retest compression.
^ If adding oil helps compression, piston rings may be worn or damaged. If so, replace piston rings after checking piston.
^ If pressure stays low, a valve may be sticking or seating improperly. Inspect and repair valve and valve seat. Refer to Engine; Specifications.
If valve or valve seat is damaged excessively, replace them.
^ If compression stays low in two cylinders that are next to each other, then the cylinder head gasket may be leaking. If so, replace cylinder head gasket.
11. Install spark plugs and fuel pump fuse.
12. Connect the distributor coil harness connector.
13. Erase DTC if any DTC appears.