Mechanical Inspection: Compression
WARNING: This page is about a different car, the 1996 Saab 9000. However, it is still accessible from the selected car via links, so may be relevant.
Check engine mechanical condition with compression gauge, vacuum gauge, or engine analyzer. See engine analyzer instruction manual for specific instructions.
CAUTION:
Use a remote starter to crank engine during compression test. DO NOT
use ignition switch. Fuel injectors on many fuel-injected models are triggered during cranking mode. This could cause a fire hazard, flooding, crankcase contamination, hydrostatic lock, or lubrication to be washed off cylinder walls.
Measure engine compression at normal operating temperature with all spark plugs removed. To prevent damage to catalytic converter, test quickly and only if necessary.
NOTE:
Compression pressures are not specified by manufacturer.
COMPRESSION RATIO
| Application | Specification |
|---|---|
| 2.3L | 9.25:1 |
| 3.0L | 10.8:1 |