Engine Compression
WARNING: This page is about a different car, the 2003 Mercury Marauder, 2003 Mercury Grand Marquis, 2003 Lincoln Town Car, and 2003 Ford Crown Victoria. However, it is still accessible from the selected car via links, so may be relevant.
Warm engine to normal operating temperature. Check compression at cranking speed with throttle wide open and all spark plugs removed. Ensure crankcase is at correct level and oil is of correct viscosity. With compression gauge installed, use remote starter to crank engine.
Crank engine 5 revolutions (minimum) and record highest pressure gauge reading. Repeat procedure for all cylinders using approximately same number of revolutions. Lowest compression reading should not be less than 75 percent of highest compression reading. Cylinder compression readings should not be less than 100 psi (7 kg/cm2 ).