How JustAnswer Works:
  • Ask an Expert
    Experts are full of valuable knowledge and are ready to help with any question. Credentials confirmed by a Fortune 500 verification firm.
  • Get a Professional Answer
    Via email, text message, or notification as you wait on our site. Ask follow up questions if you need to.
  • Go back-and-forth until satisfied
    Rate the answer you receive.
Ask Phillip H Your Own Question
Phillip H
Phillip H, ASE Certified Technician
Category: BMW
Satisfied Customers: 470
Experience:  Vehicle Technician at Richmond Motor Services
108937146
Type Your BMW Question Here...
Phillip H is online now

I have 64 REG bmw 520d and noticed it's making some kind of

This answer was rated:

Hi, I have 64 REG bmw 520d and noticed it's making some kind of pumping noise from the rear, even after shutting off engine.
JA: Have you checked the fluids recently?
Customer: you mean engine oil?
JA: What is the model of your '64 BMW?
Customer: 520d
JA: Are you fixing your vehicle yourself? What have you tried so far?
Customer: Nothing
JA: Is there anything else the Mechanic should know before I connect you? Rest assured that they'll be able to help you.
Customer: No

Hiya

It is quite normal on vehicle to hear various things running after the engine and the ignition have been turned off.

On most vehicles with Electronic Modules it takes approimately 3 minutes for all of these modules to enter thier sleep mode.  During this time they are used to check various components after shut down for fault diagnosis purposes and to ensure the vehilce is in a state ready to start again.

On most modern vehicles some of the things you may continue to hear are the following:


  1. Engine Cooling Fan (can run on for several minutes after shut down to ensure the Engine has no Hot Spots)

  2. Electric Water Pump (Runs on to ensure continued flow of Engine Coolant so as to reduce risk of Engine Hot Spots)

  3. Leak Detection Pump (EVAP System a pump is used to check there are no leaks present when the EVAP valves are closed after vehicle shut down)

  4. AdBlure Pump (runs on to ensure that there is no AdBlue in the Line to prevent freezing of the AdBlue in the Line)

I think your vehilce is too early for AdBlue so I suspect what you are hearing is the Leak Detection Pump which is usually located at the rear of the vehicle.  This is normally out of sight under one of the Wheel Arch Liners close to the Fuel Tank Filler Pipes.

Regards

Phillip

Customer: replied 17 days ago.
I see, then is there any reason why I hear the noise clearly these days but not for the past several years? FYI, my car has been regularly serviced and the next one is due next month.

Hiya

It could just be that the Leak Detectiion Pump if that is the noise could be worn and requires replacement.  It is in effect a motor which contains bearings that the motor runs in.

You would have to gain access to the pump and check it when you turn the vehicle off and see if that is the fault.  I believe it is behind the Arch Lining near the Fuel Filler Pipe.

Regards

Phillip

Phillip H and other BMW Specialists are ready to help you