Compression Check: Testing and Inspection

Engine Compression Inspection

NOTE: After this inspection, you must reset the engine control module (ECM)/powertrain control module (PCM), otherwise the ECM/PCM will continue to stop the fuel injectors from operating.

1. Warm up the engine to normal operating temperature (cooling fan comes on).

2. Turn the ignition switch to LOCK (0).

3. Connect the HDS to the data link connector (DLC). Initial Inspection and Diagnostic Overview

4. Turn the ignition switch to ON (II).

5. Make sure the HDS communicates with the vehicle and the ECM/PCM If it does not communicate, troubleshoot the DLC circuit.. Testing and Inspection

6. Select ALL INJECTORS STOP in the PGM-FI INSPECTION menu with the HDS.

7. Turn the ignition switch to LOCK (0).

8. Remove the four ignition coils. Service and Repair

9. Remove the four spark plugs.

10. Attach a compression gauge to the spark plug hole.

11. Step on the accelerator open the throttle fully, then crank the engine with the starter motor, and measure the compression.

Compression Pressure:
Above 930 kPa (9.5 kgf/cm2, 135 psi)

12. Measure the compression on the remaining cylinders.

Maximum Variation:
Within 200 kPa (2.0 kgf/cm2, 28 psi)

13. If the compression is not within specifications, check the following items, then remeasure the compression.
- Incorrect valve clearance

- Confirmation of cam timing

- Damaged or worn valves and seats

- Damaged cylinder head gasket

- Damaged or worn piston rings

- Damaged or worn piston and cylinder bore

14. Remove the compression gauge from the spark plug hole.

15. Install the four spark plugs.

16. Install the four ignition coils. Service and Repair

17. Select the ECM/PCM reset Initial Inspection and Diagnostic Overview in the PGM-FI INSPECTION menu to cancel ALL INJECTORS STOP with the HDS.