Ranger 2WD V6-245 4.0L VIN X SFI (1997)
Compression Check: Testing and Inspection
Gauge Check
1. Make sure oil in crankcase is of the correct viscosity and at proper level, and battery is properly charged. Operate vehicle until engine is at normal
operating temperature. Turn off ignition, then remove all spark plugs.
2. Set throttle plates in wide, open position.
3. Install Rotunda Compression Tester 014-00707 or equivalent in No. 1 cylinder.
4. Install an auxiliary starter switch in starting circuit. With ignition in the OFF position, and using auxiliary starter switch, crank engine at least five
compression strokes and record highest reading. Note the approximate number of compression strokes required to obtain the highest reading.
5. Repeat test on each cylinder cranking the engine approximately the same number of compression strokes.
