2. Before starting the verification procedure, check:
- engine oil condition and level;
- the condition of the battery and its state of charge. The battery must be fully charged.
3. Disconnect high voltage wires from spark plugs (see section "Spark plug").
4. Remove all spark plugs.
5. Follow the procedures necessary to prevent the engine ECU from commanding fuel injection and ignition.
6. Close the holes for the spark plugs with a clean rag and, after cranking the crankshaft with a starter, check that there are no foreign particles on the rags.
Attention:
- Keep clear of the spark plug holes while cranking the crankshaft with the starter.
- If during the pressure measurement of the end of the compression stroke into 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.
7. Install a compression gauge in the spark plug hole.
8. Turn the engine crankshaft with the starter at wide open throttle and measure the pressure at the end of the compression stroke.
The difference between the minimum pressure value in one of the cylinders and the maximum value in one of the cylinders must not exceed 70% of the maximum value.
9. If in any cylinder the pressure of the end of the compression stroke is below the minimum allowable value or the difference in pressure of the end of the compression stroke across the cylinders exceeds the maximum allowable value, then pour a little engine oil into the spark plug hole of this cylinder and repeat the measurements in paragraph "8".
Attention:
- If after oil filling the pressure at the end of the compression stroke has increased, then the causes of the malfunction are wear or damage to the piston ring and / or cylinder mirror.
- If the pressure at the end of the compression stroke 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.
10. Install spark plugs.
11. Connect high voltage wires to spark plugs.