Compression Test - Test Results

The indicated compression pressures are considered within specification if the lowest reading cylinder is within 75 percent of the highest reading. Refer to Fig 1 or Fig 2.

Fig 1: Compression Pressure Limit Chart (1 Of 2)

Courtesy of FORD MOTOR CO.

Fig 2: Compression Pressure Limit Chart (2 Of 2)

Courtesy of FORD MOTOR CO.

If one or more cylinders reads low, squirt approximately one tablespoon of engine oil on top of the pistons in the low-reading cylinders. Repeat the compression pressure check on these cylinders.