Mechanical Inspection: Compression
WARNING: This page is about a different car, the 1998 Porsche 911 and 1997 Porsche 911. However, it is still accessible from the selected car via links, so may be relevant.
Check engine mechanical condition using a compression gauge, vacuum gauge or engine analyzer. See engine analyzer manual for specific instructions. Always disconnect engine speed/reference sensor for compression tests, otherwise dangerous high voltages and insulation damage to ignition coil, high-voltage distributor and ignition leads may result.
COMPRESSION SPECIFICATIONS
| Application | Specification | |
|---|---|---|
| Compression Ratio | 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 ) | |