3 Series E46 318Ci (N46) COUPE
16 00
Fuel supply system E46 (diesel engines)
1. General
General function description for fuel systems.
2. Parts designation
1. Fuel tank
14. Service vent line
2. Electric fuel supply pump
15. Expansion tank
3. Surge chamber
16. Roll-over valve
4. Suction jet pump
17. Distributor injection pump (M47)
5. Tank expansion line
17. High-pressure pump (M57)
6. Outlet protection valve
18. Inline pump (M57)
7. Filler pipe
19. Fuel filter
8. Tank cap
20. Fuel rail (M57)
9. Refueling vent line
21. Injection nozzle
10. Fuel return line
22. Bimetallic valve
11. Fuel feed line
23. Fuel cooler
12. H-piece
24. Pressure limiting valve (M57)
13. Service vent line
3. Function description (see also drawing 5.1 / 5.2)
Fuel system (see drawing 5.1 / 5.2)
The saddle-shaped fuel tank contains the surge chamber with the electric fuel feed supply pump on its right side.
The surge chamber ensures that the fuel supply pump is properly supplied in all vehicle operating states.
The fuel is repumped from the right side of the fuel tank into the surge chamber via the suction jet pump integrated in
the tank expansion line. The suction jet pump is operated via the fuel feed line.
The outlet protection valve protects the fuel return line. The valve closes in the event of a pressure drop when the fuel
return line is damaged or disconnected.
This prevents fuel from escaping from the fuel tank in extreme vehicle positions (overturning, inclined position).
Fuel supply to engine:
M47 (see drawing 5.1)
The fuel is routed from the electric fuel supply pump via the fuel feed line and the fuel filter to the distributor injection
pump.
The distributor injection pump supplies the relevant injection nozzle.
The return fuel from the fuel injectors and the distributor injection pump is directed to the bimetallic valve, which divides
the amount of return fuel as a function of the fuel temperature.
At low fuel temperatures, the greater part of the fuel flows back into the fuel feed line ahead of the fuel filter. In this way,
the fuel is heated up faster at low outside temperatures.
At high fuel temperatures, the greater part of the fuel flows back into the fuel tank via the fuel cooler and the fuel return
RA Fuel supply system E46 (diesel engines)
BMW AG - TIS
07.02.2013 15:59
Issue status (12/2007) Valid only until next DVD is issued
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