MKT FWD V6-3.7L (2010)
Compression Check: Testing and Inspection
Compression Test
Engine
Compression Test
1. Make sure the oil in the crankcase is of the correct viscosity and at the correct level and that the battery is correctly charged. Operate the vehicle
until the engine is at normal operating temperature. Turn the ignition switch to the OFF position, then remove all the spark plugs.
2. Set the throttle plates in the wide-open position.
3. Install a compression gauge in the No. 1 cylinder.
4. Install an auxiliary starter switch in the starting circuit. With the ignition switch in the OFF position, and using the auxiliary starter switch, crank
the engine a minimum of 5 compression strokes and record the highest reading. Note the approximate number of compression strokes necessary to
obtain the highest reading.
5. Repeat the test on each cylinder, cranking the engine approximately the same number of compression strokes.
Compression Test - 3.5L Engine Test Results
The indicated compression pressures are considered within specification if the lowest reading cylinder is at least 75% of the highest reading. Refer to the
Compression Pressure Limit Chart.
If one or more cylinders reads low, squirt approximately one tablespoon of engine oil meeting Ford specification on top of the pistons in the low-reading
cylinders. Repeat the compression pressure check on these cylinders.
Compression Test - 3.5L Gasoline Turbocharged Direct Injection (GTDI) Engine Test Results
The indicated compression pressures are considered within specification if the lowest reading cylinder is at least 75% of the highest reading. Refer to the
Compression Pressure Limit Chart.
