5.2. Check of a compression in engine cylinders
1. Results of check of a compression in cylinders of the engine allow to judge a condition of details of the engine (pistons, rings, valves and laying of a head of the block of cylinders). For obtaining exact results of check the engine has to be heated-up up to the normal temperature, and the battery is completely charged.
2. Turn out spark plugs. Completely open throttle and air gates.
3. Disconnect the central high-voltage wire from an ignition distributor cover, connect it to weight.
4. Insert the compression measuring instrument into an opening for a candle 1 - го the cylinder (photo). Include a starter and you monitor indications of the manometer. On the serviceable engine pressure has to increase quickly. Low pressure after the first piston stroke and slow increase at the subsequent steps of compression indicates wear of piston rings. If after the first piston stroke pressure low, and at the subsequent steps of compression does not increase, then leak in valves or not tightness of laying of a head of the block of cylinders is the reason (also formation of cracks in a head can be the reason). Write down the greatest value of a compression and repeat the procedure for other cylinders.
5. Repeat the procedure on other cylinders.
6. If after introduction of oil to the cylinder (10-15g) the compression raised, then it is possible to draw a conclusion that piston rings are worn-out. If the compression increases slightly, then leak happens via valves, or laying of a head of the block of cylinders.
7. If the compression equally low only in two next cylinders, then is the most probable cause a laying burn-out between these cylinders.
8. If value of a compression exceeds norm, then the combustion chamber is covered with a deposit. In this case the head of cylinders should be removed and removed a deposit.
2.4 Measurement of a compression
9. At strong distinction of a compression in cylinders the car should be handed over on car repair shop for check of the block of cylinders by a pressure testing method.