Note: If high oil consumption, reduced engine power or poor fuel economy is detected, the compression should be checked.
1. Before measuring compression, check the level and condition of the engine oil. Also, check that the starter motor and battery are in good condition.
Note: It is recommended to check for engine management system trouble codes.
2. Start the engine and warm it up to a coolant temperature of 80-95°C, then stop the engine.
3. Disconnect high voltage spark plug wires.
Note: Disconnect the fuel pump connector and ignition coil connectors to prevent the ECM from commanding fuel injection and ignition.
4. Remove the spark plugs and cover the spark plug holes in the cylinder head with a clean rag.
5. Scroll the engine crankshaft with a starter to remove foreign particles from the cylinders.
Attention:
- Keep clear of the spark plug holes while cranking the crankshaft with the starter.
- If during the measurement of compression in the cylinder (as a result of cracks) If coolant, oil, fuel, etc. gets in, these substances will heat up and will be ejected under pressure from the spark plug hole, which is a dangerous phenomenon.
6. Install a compression gauge in the spark plug hole.
7. Press the accelerator pedal until the throttle is fully open.
8. Scroll the crankshaft of the engine with a starter (about 4 turns) and read the pressure gauge.
- Rated value - 1200 kPa
- Minimum allowed value:
- 2.0L/2.4L engines - 1180 kPa
- Engine 2.7 l - 1050 kPa
Note: Values given are for 250-400 rpm.
Engines 2.0 l / 2.4 l.
Engine 2.7 l.
9. Measure compression for all remaining cylinders (repeat step by step "6"-"8") and check that the compression difference between the cylinders is less than the limit.
- Maximum allowable value - no more than 100 kPa
10. If in any cylinder the compression does not correspond to the range of permissible values or the difference in compression between the cylinders exceeds the maximum permissible value, then pour a little engine oil into the hole for the spark plug of this cylinder and repeat the steps from "6" By "9".
- A) If, after filling with oil, the compression has increased, then the causes of the malfunction are wear or damage to the piston ring and / or cylinder mirror.
- b) If the compression does not increase after filling with oil, then the causes are burnt or damaged valve seats, or gas leaks (pressure) through the cylinder head gasket.
11. Reinstall spark plugs, ignition coils (2.0L/2.4L engines only), connect the high voltage spark plug wires.
- Spark plug tightening torque - 20-30 Nm