5.2. Compression check in engine cylinders
1. Results of check of a compression in engine cylinders allow to judge a condition of details of the engine (pistons, rings, valves and a lining of a head of the block of cylinders). For reception of exact results of check the engine should be heated-up to normal temperature, and the battery is completely charged.
2. Turn out spark plugs. Completely open throttle and air заслонки.
3. Disconnect the central high-voltage wire from a cover of the distributor of ignition, connect it to weight.
4. Insert a compression measuring instrument into an aperture for a candle of 1 th cylinder (photo). Include a starter and watch manometre indications. On the serviceable engine pressure should accrue quickly. Low pressure after the first piston stroke and slow increase at the subsequent steps of compression specifies in deterioration of piston rings. If after the first piston stroke pressure low, and at the subsequent steps of compression does not increase, the reason is leak in valves or not tightness of a lining of a head of the block of cylinders (the reason formation of cracks in a head also can be). Write down the greatest value of a compression and repeat procedure for other cylinders.
5. Repeat procedure on other cylinders.
6. If after oil introduction in the cylinder (10-15г) the compression has raised, it is possible to draw a conclusion on that that piston rings are worn out. If the compression increases slightly leak occurs through valves, or a lining of a head of the block of cylinders.
7. If a compression equally low only in two next cylinders most a plausible reason is the lining burn-out between these cylinders.
8. If value of a compression exceeds norm the combustion chamber is covered by a deposit. In this case a head of cylinders it is necessary to remove and remove a deposit.
2.4 Measurement of a compression
9. At strong distinction of a compression in cylinders it is necessary to hand over the car on a car repair shop for check of the block of cylinders by a method опрессовки.