5.2. Compression check 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 receiving 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 zaslonka.
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 opening for a candle 1 - го the cylinder (photo). Include a starter and watch manometer 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 indicates wear 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 laying 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 (10-15g) the compression raised, it is possible to draw a conclusion on that that piston rings are worn-out. If the compression increases slightly, leak occurs via valves, or laying of a head of the block of cylinders.
7. If the compression equally low only in two next cylinders, the most probable cause is a laying burn-out between these cylinders.
8. If value of a compression exceeds norm, the chamber of combustion is covered with a deposit. In this case a head of cylinders it is necessary to remove and remove a deposit.
2.4 Compression measurement
9. At strong distinction of a compression in cylinders it is necessary to hand over the car on car repair shop for check of the block of cylinders by an opressovka method.