FixVault

Mechanical Inspection: Compression

WARNING: This page is about a different car, the 1995 Jaguar XJS, 1995 Jaguar XJR, and 1995 Jaguar XJ6. However, it is still accessible from the selected car via links, so may be relevant.

Check engine mechanical condition with a compression gauge, vacuum gauge, or an engine analyzer. See engine analyzer manual for specific instructions. Release fuel system pressure before checking engine compression. See FUEL SYSTEM  .

COMPRESSION SPECIFICATIONS

Application Specification
Compression Ratio
Base Engine 10.0:1
Supercharged Engine 8.5:1
Compression Pressure (1) 157-167 psi (11.0-11.7 kg/cm2 )
Maximum Variation Between Cylinders 10 psi (.70 kg/cm2 )
(1) Minimum cranking speed is 300 RPM with all spark plugs removed and throttle held wide open.