Opel Omega

since 1993-1999 release

Repair and operation of the car

Opel Omega
+ 1. Maintenance instruction
+ 2. Maintenance
+ 3. Repair of engines
+ 4. Heating system and ventilation
- 5. Fuel, exhaust systems
   + 5.1. Petrol engines
   - 5.2. 2,0 liters diesel engine
      5.2.1. Technical characteristics
      5.2.2. Air filter and air inlet channels
      5.2.3. Accelerator pedal
      5.2.4. Filling and pumping of fuel system
      5.2.5. Fuel level sensor
      5.2.6. Fuel tank
      5.2.7. Check and adjustment of the maximum turns
      5.2.8. Electric knots of system of injection
      5.2.9. Fuel pump of high pressure
      5.2.10. Fuel injection moment
      5.2.11. Fuel nozzles
      5.2.12. Turbocharger
      5.2.13. Inlet collector
      5.2.14. Final collector
   + 5.3. Diesel V6 engine of 2,5 liters
+ 6. System of start of the engine
+ 7. System of ignition
+ 8. Coupling
+ 9. Transmissions
+ 10. Main transfer, half shafts
+ 11. Brake system
+ 12. Suspension bracket and steering
+ 13. Body
+ 14. Body electric equipment


5.2. 2,0 liters diesel engine



There are two versions of the engine of 2 l: with a turbo-supercharging of the low pressure (X20DTL) and with a turbo-supercharging of the high pressure (X20DTH).

The fuel system consists of the car of the fuel tank, the fuel filter installed under a back part with a separator of water, the fuel pump of high pressure, fuel nozzles and pipelines. Before receipt in the filter fuel heats up an electric heater which is attached to the filter case.

Supply of fuel from the fuel filter to the fuel pump of high pressure is provided with the pumping-up bladed pump located in the fuel pump of high pressure. Excess fuel greases the fuel pump of high pressure and comes back to the fuel tank.

The drive of the fuel pump is carried out by a gear belt. Speed of rotation of the fuel pump is twice less than the speed of rotation of a bent shaft.

The fuel pump is operated with the help of electronic system. The system consists of the electronic control device (ECU), the control unit of the fuel pump and the following sensors:

  – the sensor of management of a pedal of an accelerator reports to ECU the provision of a pedal of management of supply of fuel;
  – the sensor of temperature of cooling liquid reports to ECU engine temperature;
  – the sensor of temperature of the arriving air reports ECU air temperature passing through the inlet channel, the sensor of temperature of oil reports to ECU engine temperature;
  – the measuring instrument of a stream of air reports to ECU amount of the air passing through the inlet channel;
  – the sensor of a bent shaft reports the relative provision of a bent shaft and frequency of its rotation;
  – the sensor of pressure reports relative pressure in a final collector;
  – the ABS system reports to ECU the relative speed of the car;
  – the switch of the compressor of the air conditioning system reports to ECU about inclusion of air conditioning system.

On the basis of information obtained from sensors, ECU defines the moment of injection of fuel at all temperatures and power setting. ECU also operates system of repeated combustion of exhaust gases and system of prestarting heating of the engine.

Fuel nozzles spray fuel in the vortex cameras located in a head of the block of cylinders. Fuel nozzles have to open and be closed with strictly certain pressure. The needle of a fuel nozzle is greased with fuel which collects about a spring and goes on a returnable hose to the fuel pump.

In an inlet collector the throttle valve for improvement of overall performance of the engine on low turns is installed. In each cylinder air moves on two channels in an inlet collector in one of which the valve operated by the ECU block via the electromagnetic valve and a vacuum diaphragm is installed. At turns less than 1 500 rpm valves are closed, and air comes to cylinders only on one channel. On higher turns of the engine the ECU block opens valves therefore air comes to each cylinder via both channels of an inlet collector.

Full check of system of injection can be executed when using the special electronic diagnostic equipment which turns on in the diagnostic socket of fuel system. The diagnostic socket is located behind the central console in front of the lever of the emergency brake.


The turbocharger works at extremely high speeds and temperatures. Do not use a turbocharger at the removed any part or a hose. The foreign particles getting on the rotating blades can damage a turbocharger.

Do not increase engine turns at once after start, especially on the cold engine. It is necessary to wait at least several seconds for ensuring normal circulation of oil.

Give the chance to the engine to work in the idling mode within several minutes before switching off after operation of the engine on high turns.

For lubricant of the engine use only oil of the recommended quality.