Compression Test

AllData Editors Note - Ford does not provide a cranking pressure specification, only an acceptable range.

NOTE: Removing fuses and disconnecting electrical components causes the Powertrain Control Module (PCM) to come up with an error message. After measurement has been carried out this error message should be cleared from memory by connecting NGS.

NOTE: Only check the compression pressure with the valves set to the prescribed clearance (if this can be adjusted).

The compression pressure should be checked with the engine at operating temperature.
Differing designs of compressor pressure recorder and varying starter motor speeds usually only make it possible to check that the compression is the same in all cylinders.