Mariner 2WD V6-3.0L (2008)
Compression Check: Testing and Inspection
Compression Test - Test Results
Compression Test - 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.
Compression Pressure Limit Chart
Compression Pressure Limit Chart (Part 1)
Compression Pressure Limit Chart (Part 2)
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 - Interpreting Compression Readings
1. If compression improves considerably, piston rings are worn or damaged.
2. If compression does not improve, valves are sticking or not seating correctly.
3. If 2 adjacent cylinders indicate low compression pressures and squirting oil on each piston does not increase compression, the head gasket may be
leaking between cylinders. Engine oil or coolant in cylinders could result from this condition.
