Engine Compression Inspection

WARNING: This page is about a different car, the 2011 Honda Pilot, 2010 Honda Pilot, and 2009 Honda Pilot. However, it is still accessible from the selected car via links, so may be relevant.

NOTE: After the inspection, you must reset the powertrain control module (PCM). Otherwise, the PCM will continue to stop the fuel injectors from functioning.

Warm up the engine to normal operating temperature (cooling fan comes on).
Turn the ignition switch to LOCK (0).
Connect the Honda Diagnostic System (HDS) to the data link connector (DLC) (see step 2 on GENERAL TROUBLESHOOTING INFORMATION ).
Turn the ignition switch to ON (II).
Make sure the HDS communicates with the vehicle and the PCM. If it doesn't communicate, troubleshoot the DLC circuit (see DLC CIRCUIT TROUBLESHOOTING ).
Select ALL INJECTORS STOP in the PGM-FI, INSPECTION, with the HDS.
Turn the ignition switch to LOCK (0).
Remove the six ignition coils (see IGNITION COIL REMOVAL/INSTALLATION ).
Attach the compression gauge to a spark plug hole.

Fig 1: Attaching Compression Gauge To Spark Plug Hole

Courtesy of AMERICAN HONDA MOTOR CO., INC.

Step on the accelerator pedal to open the throttle, then crank the engine with the starter motor, and measure the compression.
Compression Pressure:

930 kPa (9.5 kgf/cm ² , 135 psi)
Measure the compression on the remaining cylinders.
Maximum Variation:

200 kPa (2.0 kgf/cm ² ,28 psi)
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 cam lobes
- Damaged or worn valves and seats
- Damaged cylinder head gaskets
- Damaged or worn piston rings
- Damaged or worn piston and cylinder bore
Remove the compression gauge from the spark plug hole.
Install the six ignition coils & six spark plugs.(see IGNITION COIL REMOVAL/INSTALLATION )
Select PCM reset (see GENERAL TROUBLESHOOTING INFORMATION ) in the PGM-FI to cancel ALL INJECTORS STOP with the HDS.