Fuel Pump
Fuel Pump
Section titled “Fuel Pump”The E46 uses an in-tank electric fuel pump to deliver fuel to the engine at approximately 3.5 bar (50 PSI).
Symptoms of Failure
Section titled “Symptoms of Failure”- Engine cranks but won’t start
- Stalling or hesitation under load
- Whining noise from fuel tank area
- Loss of power at high RPM
- Long cranking before starting
Diagnosis
Section titled “Diagnosis”- Listen for pump priming when key is turned to position 2
- Check fuel pressure at rail (should be ~3.5 bar)
- Scan for fuel pressure-related fault codes
Replacement
Section titled “Replacement”- Fuel pump is accessed through panel under rear seat
- Replace fuel filter at same time
- Replace O-ring seal on sender unit