Focus ZX5 L4-2.0L DOHC VIN 3 (2002)
2. Pull off the spark plug connectors and remove the spark plugs.
3. Pull off the ignition coil connector.
NOTE: Operate the starter motor with wide open throttle until the pointer on the measuring device stops rising.
4. Using Special Tool 164-R0253 carry out the measurement on every cylinder.
NOTE: Coat the spark plug connector gasket with silicone grease (A960-M1C-M) before installing it.
5. Installing the components in reverse order, keeping to the specified tightening torques: coat the spark plug thread with spark plug lubricant.
Cylinder head cover tightening torque: Stage 1: 2 Nm,. Stage 2: 7 Nm. Spark plug tightening torque: 15 Nm.
6. Reset the PCM fault memory.
Interpretation of the Results
The indicated compression pressure are considered within specification if the lowest reading cylinder is within 75% of the highest reading.
CAUTION: If engine oil is sprayed into the combustion chamber, after carrying out the measurement run the engine at 2000 rpm for about 15
minutes, in order to burn the oil and prevent damage to the catalytic converter.
If the measurement on one or more cylinders is much lower than the specified value, spray some engine oil into the combustion chamber and repeat
the compression measurement.
If the reading greatly improves then the piston rings are damaged.
If the reading stays the same then the cause is either bad valve seats or valve stem oil seals.
If the measurements for two cylinders next to each other are both too low then it is very likely that the cylinder head gasket between them is burnt
through. This can also be recognized by traces of engine oil in the coolant in the engine oil.
