Engine Compression

Check engine compression with engine at normal operating temperature, all spark plugs removed and throttle wide open.

COMPRESSION SPECIFICATIONS

Application

Specification

Compression Ratio

4.6L

10.3:1

4.9L

9.5:1

Normal Compression Pressure
⁽¹⁾

Minimum Compression Pressure
⁽¹⁾

⁽¹⁾	Lowest compression reading should not be less than 70 percent of highest compression reading. No cylinder compression reading should be less than 100 psi (7 kg/cm² ).