2. Relieve pressure in the supply system.
3. Remove coils and spark plugs from each cylinder.
4. Connect the tachometer to the engine (not necessary when using CONSULT-III).
5. Install a compression gauge (IN) with adapter (A) into the spark plug hole.
Note. Use an adapter with an insertion diameter of at least 20 mm, otherwise it may slip into the cylinder and cause engine damage.
6. With the accelerator pedal fully depressed, turn the ignition switch to the «START» to turn the crankshaft of the engine with a starter. After the readings of the arrow of the compression gauge stabilize, read the compression value and the engine speed. Carry out the described procedure for each engine cylinder.
Attention. To check the compression in the engine cylinders, it is necessary to use a fully charged battery to obtain the required crankshaft speed.
Note.
- If the crankshaft speed does not match the required, check the tightness
- electrolyte in the battery. Make sure the battery is fully charged and repeat the measurement of the crankshaft speed.
- IF the compression values are below the limit, check the valve clearances and the condition of the parts associated with the combustion chamber (valves, valve seats, pistons, piston rings, cylinder bore, cylinder head, head gasket). After checking, check the compression in the cylinders again.
- In a cylinder with a low compression value, add a small amount of oil through the spark plug hole and check the compression again:
- If, after adding oil, the compression in these cylinders increased, then the piston rings are most likely worn or destroyed. Check the condition of the piston rings and, if necessary, replace them with new ones.
- If compression remains low, the cause may be poor condition of the valves and/or valve seats. Check the condition of the valves and seats for damage. Replace valve or valve seat.
- If a low compression value is observed in neighboring cylinders, then a defective cylinder head gasket may be the cause. Replace the defective gasket with a new one.
7. After checking, install the removed parts.
8. Start the engine and check that it runs smoothly.
9. Perform troubleshooting. If necessary, clear stored trouble codes.