Gasoline Engines
WARNING: This page is about a different car, the 2003 Mercury Mountaineer, 2003 Lincoln Aviator, 2003 Ford Explorer Sport Trac, 2003 Ford Explorer Sport, and 2003 Ford Explorer. However, it is still accessible from the selected car via links, so may be relevant.
NOTE:
DO NOT use ignition switch to crank engine. Fuel injection and coils will activate and may cause damage.
Check engine compression with engine at normal operating temperature, all spark plugs removed (on dual plugs, remove exhaust side only), and throttle wide open. Ensure crankcase is full and oil is of correct viscosity. With compression gauge installed, use remote starter switch to crank engine.
Crank engine at least 5 revolutions, and record highest 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. No cylinder compression reading should be less than 100 psi (7 kg/cm2 ).