Engine Compression

WARNING: This page is about a different car, the 1995 Cadillac Seville and 1995 Cadillac DeVille. However, it is still accessible from the selected car via links, so may be relevant.

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 ).