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 ignition coils.
5. Remove spark plugs.
^ Clean area around plug with compressed air before removing the spark plug.
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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 as shown above.
^ Always use a fully-charged battery to obtain specified engine speed.
Compression pressure: (kPa (bar, kg/cm2, psi)/rpm)
Standard:
1,324 (13.24, 13.5, 192)/350
Minimum:
1,157 (11.57, 11.5, 168)/350
Maximum allowable difference between cylinders:
98 (0.98, 1.0, 14)/350
10. If cylinder compression in one or more cylinders is low, pour a small amount of engine oil into the cylinder through the spark plug hole and retest compression.
^ If adding oil improves cylinder 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 in any two adjacent cylinders is low and if adding oil does not improve compression, there is leakage past the gasket surface. If so, replace cylinder head gasket.
11. Install spark plugs, ignition coils and fuel pump fuse.
12. Erase DTC if any DTC appears.