Focus L4-2.0L SOHC VIN P (2000)
NOTE: Operate the starter motor with wide open throttle until the pointer on the measuring device stops rising.
6. Carry out the measurement in accordance with the instructions supplied with the measuring device on every cylinder using Special Tool
164-RO253.
NOTE: Coat the spark plug connector gasket with silicone grease (A960-M1C-AA) before installing.
7. Install the components in reverse order, keeping to the specified tightening torques: coat the spark plug thread with spark plug lubricant.
Tightening torque for spark plugs: 15 Nm.
8. Repeat the test on each cylinder.
9. 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 coolant in the engine oil.
