Cylinder Compression Pressure

WARNING: DO NOT use ignition switch during compression tests on fuel injected vehicles. Use a remote starter to crank engine. Fuel injectors on many models are triggered by ignition switch during cranking mode, which can create a fire hazard or contaminate the engine's oiling system.

Check engine mechanical condition with a compression gauge, vacuum gauge, or scan tool. See scan tool manual for specific instructions. Ensure battery is fully charged, engine is at normal operating temperature and throttle valve is fully open when checking compression. Remove Auto Shutdown relay from Integrated Power Module (IPM). IPM is located on left side of engine compartment, next to battery. Clean spark plug recesses with compressed air. Remove all spark plugs. Install compression gauge into No. 1 spark plug hole. Hold throttle in Wide Open Throttle (WOT) position. Crank engine until maximum pressure is reached. Note pressure reading and repeat for remaining cylinders. See COMPRESSION SPECIFICATIONS table for correct engine compression pressures.

COMPRESSION SPECIFICATIONS

Application

psi (kg/cm² )

Normal Compression Pressure

⁽¹⁾

Minimum Compression Pressure

100 (7)

Maximum Variation Between Cylinders

⁽²⁾

⁽¹⁾	Information is not available from manufacturer.

⁽²⁾	Maximum variation is 25 percent.

Fig 1: Locating Integrated Power Module & Powertrain Control Module

Courtesy of DAIMLERCHRYSLER CORPORATION

Fig 2: Identifying Integrated Power Module Components

Courtesy of DAIMLERCHRYSLER CORPORATION