3.1.16. Compression

Check of a compression allows to draw conclusions on a condition of the engine. At its check it is possible to establish whether valves or pistons (piston rings) are normal or they are worn-out. Besides, by results of control it is possible to define whether the engine is subject to replacement or it can be repaired in a complex. For check the device is necessary for control of a compression.

Pressure difference between separate cylinders has to make at most 1,5 bars. If the difference in pressure makes more than 1,5 bars, then it is a sign of defective valves, worn-out piston rings or guides of the cylinder. If reach a wear limit, the engine needs to be repaired or replaced.

Pressure of compression has to make: for the 4-cylinder engine of 10-14 bars, for 6-cylinder about 12 bars.
1. For control of a compression warm up the engine. After achievement of working temperature of cooling liquid pass 5 more km to provide the sufficient temperature of engine oil.
2. Raise an engine cowl.
3. 1,8 / 2,0 l engine: switch off ignition. Disconnect the sensor of a position of a bent shaft (L5) from the PMS monitor.
4. 2,2 / 2,8 l engine: switch off ignition. Remove a monitor covering behind a forward wall of a body. Disconnect the plug (A) from the HFM monitor (N3/4).
5. Unscrew all spark plugs.
6. Several times scroll the engine a starter to remove deposits and soot.

Install the transmission in the provision of idling and tighten the parking brake. During scrolling do not bend over the engine: danger of a trauma!

7. Insert the device of control of a compression (01) according to the maintenance instruction or twist a rod (04) in a spark plug opening. Enter a new leaf for the chart (03), (02) an intermediate detail.
8. Charge to the assistant to press an accelerator pedal against the stop and to hold it until the end of the check pressed.
9. The engine has to make about eight turns, rise in pressure by the measuring device will not be fixed yet.
10. One by one check all cylinders and compare to nominal rate.
11. Then insert spark plugs.
12. At the switched-off ignition put on the sensor of a position of a bent shaft PMS or the HFM monitor. Establish a cover of the operating HFM device.
13. Close a cowl.