Engine Compression Test (SOHC & DOHC)

Note: Perform this test with the engine cold.

Preparation

1. Remove intercooler (DOHC Turbo).
2. Remove air intake tank (SOHC).
3. Disconnect the crank sensor connector.

Note: Failure to disconnect the crank sensor circuit will cause the spark plugs to fire while the engine is cranked for the test.

Note: If the oil is dirty or thin, the test may not give an accurate result — only test compression with clean oil. If the oil was recently changed, run the engine a minimum of 5 minutes first, then shut off and allow the engine to cool to ambient temperature before testing.

Procedure

1. Remove spark plugs one at a time.
2. Attach a compression gauge as shown.
3. Turn the engine over (default starter speed 400 RPM).
4. Remove the gauge and reinstall the spark plug.
5. Continue and complete testing on all 4 cylinders.

Compression specification

Engine	Compression @ 400 RPM cranking
SOHC	11.5 kg/cm² (164 psi)
DOHC Turbo	9.0 kg/cm² (128 psi)

(verify printed p.28) — the source labels these values “SOHC 2 Valve” and “SOHC-DOHC 5 Valve Turbo” rather than plainly SOHC/DOHC; see the labeling caveat in Section 8. The SOHC/DOHC split above follows the value ordering, which is consistent between this page and the printed p.22 summary table.

Results interpretation

If a spread of 1 kg/cm² (14 psi) is recorded between the 4 cylinders, further investigation may be required. On vehicles with over 100,000km (62,137mi), it is recommended to replace the piston rings. Always replace piston rings as a set — see the Engine Overhaul section of this manual for details.