Mechanical Inspection: Compression
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.
COMPRESSION SPECIFICATIONS
| Application | Specification | |
|---|---|---|
| Compression Ratio | ||
| ES300 | 9.5:1 | |
| LS400 & SC400 | 10.0:1 | |
| SC300 | 10.2:1 | |
| Compression Pressure | 178 psi (12.5 kg/cm2 ) | |
| Minimum Compression Pressure | 142 psi (10 kg/cm2 ) | |
| Maximum Variation | ||
| Between Cylinders | 14 psi (1.0 kg/cm2 ) | |