Mechanical Inspection: Compression

NOTE: Engine compression specification for the Defender 90 is not available from manufacturer.

Check engine mechanical condition with a compression gauge, vacuum gauge, or an engine analyzer. See engine analyzer user manual for specific instructions. See ENGINE COMPRESSION SPECIFICATIONS (DISCOVERY) table. Engine compression ratio specification is displayed above engine identification code. Engine identification code is stamped on a cast pad located between cylinders No. 3 and No. 5. See Fig 1 .

Fig 1: Engine Identification Code & Engine Compression Ratio (CR)

Courtesy of LAND ROVER NORTH AMERICA, INC.

WARNING: DO NOT use ignition switch during compression tests on fuel injected vehicles. Use a remote starter switch to crank engine. Fuel injectors and fuel pump are activated by ignition switch during cranking mode, which can create a fire hazard or contaminate the engine's oiling system.

ENGINE COMPRESSION SPECIFICATIONS (DISCOVERY)

Application		Specification
Normal Compression Pressure
8.31:1		150-160 psi (10-11 kg/cm² )
9.35:1		170-180 psi (12-13 kg/cm² )