Check engine mechanical condition with a compression gauge, vacuum gauge, or an engine analyzer. See engine analyzer manual for specific instructions.

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 compression with engine at normal operating temperature, all spark plugs removed and throttle wide open. See COMPRESSION SPECIFICATIONS table.

COMPRESSION SPECIFICATIONS

Application ⁽¹⁾

Specification

Compression Ratio

1.5L (VIN A)

9.0:1

1.8L (VIN C)

9.5:1

2.0L

(VIN F)

8.5:1

(VIN Y)

9.6:1

2.4L (VIN G)

9.5:1

3.0L

(VIN H)

8.9:1

(VIN J)

10.0:1

(VIN K)

8.0:1

(VIN P)

9.0:1

3.5L (VIN M & P)

9.0:1

Compression Pressure

1.5L (VIN A)

192 psi (13.4 kg/cm² )

1.8L (VIN C)

199 psi (13.9 kg/cm² )

2.0L (VIN F)

178 psi (12.5 kg/cm² )

2.0L (VIN Y)

170-225 psi (11.7-15.5 kg/cm² )

2.4L (VIN G)

192 psi (13.4 kg/cm² )

3.0L

(VIN H & P)

171 psi (12.0 kg/cm² )

(VIN J)

185 psi (13.0 kg/cm² )

(VIN K)

156 psi (10.9 kg/cm² )

3.5L (VIN M & P)

171 psi (12.0 kg/cm² )

Maximum Variation Between Cylinders ⁽²⁾

14 psi (1.0 kg/cm² )

⁽¹⁾	See ENGINE/VIN ID article for VIN information.

⁽²⁾	On Eclipse 2.0L non-turbo engine, maximum variation between cylinders is 25%.

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

Mechanical Inspection: Compression

Use the Manual With the Right Hardware

When to See a Mechanic