Engine Compression
Deactivate fuel injection system by removing main fuel injection relay prior to compression test. Fully charge battery. Check compression with engine at normal operating temperature, throttle fully open, and engine at cranking speed.
COMPRESSION SPECIFICATIONS
| Application | Specification | |
|---|---|---|
| Compression Ratio | ||
| 325 | 8.5:1 | |
| 325i, 325iC & 325iS | 8.8:1 | |
| 535iS | 8.0:1 | |
| 528e, 635CSi & 735i | 9.0:1 | |
| Compression Pressure | ||
| All Engines | 142-156 psi (10-11 kg/cm2 ) | |