Deactivate fuel injection system by removing Digital Motor Electronics (DME) master relay and fuel pump relay before performing compression test. See DME & FUEL PUMP RELAY LOCATION table. Ensure battery is fully charged.
Ensure engine coolant temperature does not exceed 86°F (30°C). Remove oil filler cap. Remove 2 nut covers and nuts securing cylinder head cover(s). Remove cylinder head cover(s). Disconnect ignition coil connectors.
Remove ignition coils. Using 16-mm Socket (12-1-171) and Torque Limiter (12-1-172), remove spark plugs. Use Pressure Gauge (11-0-162), Test Adapter (11-0-166) and Tube Extension (11-0-167) to check compression pressure. See COMPRESSION SPECIFICATIONS table.

COMPRESSION SPECIFICATIONS

Application	Specification
Compression Ratio	10.2:1
Compression Pressure	142-156 psi (10-11 kg/cm² )

DME & FUEL PUMP RELAY LOCATION

Application

Location

6-Cyl.

⁽¹⁾ Behind Cover, Along Engine Compartment Firewal

⁽¹⁾	First relay (viewed from left to right) after ground wire is fuel pump relay followed by Digital Motor Electronics (DME) master relay.

When to See a Mechanic

Stop DIY work and contact a certified mechanic immediately if any of the following apply:

• You smell fuel, burning insulation, or see smoke.

• Brakes feel soft, pull hard to one side, or make grinding noises.

• The engine overheats, stalls repeatedly, or misfires under load.

• You are missing required tools, torque specs, or safe lifting equipment.

• You are not confident in the next step or safety outcome.

Safety Warning

Engine Compression