Mustang GT V8-4.6L SOHC VIN X (1998)
Compression Check: Testing and Inspection
Compression Test
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 ignition switch to the OFF position, then remove all spark plugs.
2. Install a compression gauge such as Rotunda Compression Tester 164-R0250 or equivalent in No.1 cylinder.
3. Install an auxiliary starter switch in starting circuit. With ignition switch in the OFF position, and using auxiliary starter switch, crank engine a
minimum of five compression strokes and record highest reading. Note the approximate number of compression strokes required to obtain the
highest reading.
4. Repeat test on each cylinder, cranking the engine approximately the same number of compression strokes.
