Mechanical Inspection: Compression
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 an engine analyzer. See engine analyzer manual for specific instructions. Ensure battery is fully charged and throttle valve is fully open when checking the compression. On 2.4L, 3.3L and 3.8L, ensure electrical connector is disconnected from ignition coil to prevent engine from starting when performing compression test. On 3.0L, remove ignition coil wire from distributor cap and connect to engine ground to prevent engine from starting when performing compression test.
COMPRESSION SPECIFICATIONS
| Application | psi (kPa) | |||||
|---|---|---|---|---|---|---|
| Normal Compression Pressure | ||||||
| 2.4L | 170-225 (1172-1551) | |||||
| 3.0L | 178 (1227) | |||||
| 3.3L & 3.8L | (1) | |||||
| Minimum Compression Pressure | 100 (690) | |||||
| Maximum Variation Between Cylinders | (2) | |||||
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