Audi 100/A6

1990-1997 of release

Repair and car operation

3.1.3.9. Compression check

THE GENERAL DATA

Compression check allows to draw conclusions on an engine condition. Namely, at check it is possible to establish, silt valves and pistons (piston rings) is perfectly in order, or they are worn out. Besides, results of check show, whether to replace the engine or to it the complete repair is required. For check it is required компрессометр which for petrol engines is offered in specialised shops under the reasonable price.

As much as possible admissible difference of pressure in separate cylinders can make 3,0 bar (for diesel engines 5,0 bar). In case one or several cylinders in comparison with others have a difference of pressure more than 3,0 bar it is instructions on the defective valves, the worn out piston rings or working surfaces of cylinders. If the deterioration border it is necessary to repair or replace the engine is reached.

The engine	Pressure of a compression, bar (new)	Pressure of a compression, bar (deterioration border)
The petrol 6-cylinder	11–16	9

Compression check should be carried out on the heated-up engine. The engine temperature should make at least 30 With.

PERFORMANCE ORDER

1. Ignition switch off. 2. The tip of the target cascade of pressure of the coil of ignition pull out. The target cascade of pressure is near to the ignition coil. At the 6-cylinder engine it is necessary to pull out 2 tips. 3. Take out safety lock N17 (for the fuel pump) from a box of safety locks. 4. Pull out all electric tips клапанных atomizers. On engines with system Mono-Motronic available there is only one клапанная an atomizer. 5. Pull out all tips of spark plugs. For this purpose there is a special bar, for example HAZET 1849. 6. Then tips need to be placed in steel cartridges if those are available. 7. After that blow compressed air of a niche of spark plugs in a head of cylinders and turn out all candles a suitable key. 8. Turn the engine few times a starter to throw out adjournment of a deposit and soot. The prevention Transmission switch to neutral transfer and include a manual brake. 9. Компрессометр according to a management on service press to an aperture for a candle or screw. The assistant should drown completely a pedal of gas and during all check to keep her foot. 10. The engine turn approximately on eight turns while change of indications on a device scale will not stop. 11. Check up consistently all cylinders and compare the received values to the recommended. 12. After that screw spark plugs and insert ignition wires. 13. Insert the tip of the target cascade of pressure. 14. Insert the tip клапанной atomizers. 15. Insert safety lock N17 into a box of safety locks.