Opel Omega

since 1993-1999 of release

Repair and car operation

Opel Omega
+ 1. Maintenance instruction
+ 2. Maintenance
- 3. Repair of engines
   + 3.1. SOHC engines in volume 2,0 liters
   + 3.2. DOHC engines in volume 2,0 liters
   + 3.3. Engines in volume 2,5 and 3,0 liters
   - 3.4. Partition of all petrol engines
      3.4.1. Technical characteristics
      3.4.2. Compression check
      + 3.4.3. Engine partition
      3.4.4. Auxiliary elements of the engine
      + 3.4.5. Engine
      3.4.6. Engine partition
      3.4.7. Head of cylinders and valves
      3.4.8. Pistons and rods
      3.4.9. Cranked shaft
      3.4.10. Block of cylinders
      3.4.11. Radical bearings and bearings of rods
      3.4.12. Piston rings
      3.4.13. The first start of the engine after a partition
   + 3.5. Diesel engine in volume 2,0 liters
   + 3.6. Diesel six-cylinder 2,5-liter engine
+ 4. Heating system and ventilation
+ 5. Fuel, exhaust systems
+ 6. System of start of the engine
+ 7. Ignition system
+ 8. Coupling
+ 9. Transmissions
+ 10. Main transfer, semi-axes
+ 11. Brake system
+ 12. Suspension bracket and steering
+ 13. Body
+ 14. Body electric equipment

3.4.2. Compression check


If the engine works badly or with interruptions, check system of ignition and fuel system. If it was not possible to find the reason of bad operation of the engine, inspect a compression. Regular carrying out this check will allow you to prevent emergence of malfunctions in advance also.

For carrying out check the engine should be warmed up, the accumulator should be charged, and spark plugs should be unscrewed.

1. Disconnect ignition system, having disconnected a wire of a high voltage of the coil of ignition from a cover of the distributor of ignition. Earth a wire on the block of cylinders.
2. Connect the device for compression measurement to an opening of a spark plug of the N1 cylinder.
3. Completely open a butterfly valve and scroll a cranked shaft of the engine a starter. After one or two turns pressure of compression should raise to the maximum mark, and then be stabilized. Write down the received result.
4. Carry out similar check with other cylinders and write down the received indications.
5. Pressure in all cylinders should be identical. The difference more than in the 2nd bar between any two cylinders means malfunction. In the serviceable engine pressure should accrue quickly. The small pressure of the first step which is gradually raising at the subsequent steps, specifies that piston rings are worn-out. Small pressure of the first step which does not accrue at the subsequent steps, indicates leak in valves or on the punched laying of a head. Deposits on the lower parts of valves can become the reason of a low compression also.
6. If at carrying out check you have doubts, address to experts.
7. If pressure, in any cylinder too low, carry out the following check to establish the reason.
8. Pour in a teaspoon of pure engine oil in the cylinder through an opening of a spark plug and repeat pressure check.
9. If after oil addition pressure of compression increased, it means that the piston or the cylinder is worn-out. If pressure did not increase, means, the reason in the worn-out or scorched valves or in the punched laying of a head of cylinders.
10. Low pressure in two next cylinders practically always means that between them head laying is punched.
11. If in one of cylinders pressure approximately for 20 % is lower, than in the others, and the engine badly idles, it means that the reason, probably, the worn-out cam of a camshaft is. If pressure very high, possibly, chambers of combustion are covered with carbon deposits.
12. After completion of check screw in spark plugs on places and connect ignition system.