Engine Compression
Check engine compression with engine at normal operating temperature and specified cranking speed, all spark plugs removed (on dual plugs, remove exhaust side only) and throttle wide open.
COMPRESSION SPECIFICATIONS
| Application | Specification | |
|---|---|---|
| Compression Ratio | ||
| 911 Carrera, 911 Carrera 4 | 11.3:1 | |
| Compression Pressure | ||
| Normal | 142-184 psi (10-13 kg/cm2 ) | |
| Minimum | 107 psi (7.5 kg/cm2 ) | |
| Maximum Variation | ||
| Between Cylinders | 22 psi (1.5 kg/cm2 ) | |