1. The results of the compression test in the engine cylinders allow us to judge the condition of the engine parts (pistons, rings, valves and seats, cylinder head gaskets).
2. To obtain accurate test results, the engine must be warmed up to normal temperature and the battery fully charged.
3. Turn off the ignition system, mark and disconnect high-voltage wires from the candles and turn out the candles. Further verification is recommended to be performed by two people.
4. Fully open the throttle.
5. Insert a compression gauge into the spark plug hole of the 1st cylinder (photo).
6. Turn on the starter for 5 seconds and record the highest compression value.
7. Repeat the procedure for the remaining cylinders, including the starter for the same time.
8. Compare the readings in the compression in the cylinders. The compression value is considered normal if the lowest value is at least 75% of the highest reading.
9. If the compression is too low, pour about a tablespoon of oil into the cylinder. If after the introduction of oil into the cylinder, the compression increased, then we can conclude that the piston rings are worn out. If the compression increases slightly, then the leak is through the valves, or the head gasket.
10. If the compression is equally low only in two neighboring cylinders, then the most likely cause is a burnt gasket between these cylinders.