Residual (Parking) Heater Noise

[5wany]

Hi

I have noticed that there is a slight pulse (thumping) sound from my residual park heater.

(This is the heater that once you stop the car you press the fan button and the residual heat from the engine keeps the car warm for 15min or so.)

You can only hear the noise if the fan is on its lowest setting (1 green bar), its a cyclic noise, you here it about every 2 secs. Once you put the fan speed up the fan noise drowns out the thump/knock/pulse noise.  Sound seems to come from footwell at front.

Just wondered if this is normal or if other forum members fans run silent?

Car is still under warranty - so will contact Dealers, just wanted info from others in case they try the "Oh sir thats seems normal" routine.  Personally I don't think it is normal ???

I've posted here as I doubt BMW have changed the system from the e53 model (though I could be wrong).

Cheers

[jaynana]

the pulsating noise is the fuel pump of the aux heater.

should be louder from outside, you'll notice that its coming from underneath the car.

if that's the noise its perfectly normal.

[5wany]

I have the aux heater, but that is activated when car is cold and fuel pump provides fuel to webasto to create heat for fan to blow into car. 

But noise is when on residual heater - all e70 X5's have this function & i'm sure my e53 had it. 

After driving car and its at normal operating temp.  If you switch engine off / remove key, then press the blower fan +(large fan) or - (small fan) button, the fan will operate and blow heat into the cabin, the heat comes from what is stored in the engine bay, thats why its call the residual heater.  Instructions can be found on pg 122 under residual heat in the manual.  Its when on this function that I hear the noise.

Would be keen to find out what other members cars sound like.

[Steamyrotter]

Its most probably a pump for the coolant system to circulate the coolant through the heater matix & engine to get the residual heat out.

Only a guess as i haven't got it..

[psychosis]

I've used mine a few times when waiting for the kids and the only thing I can hear is the fans. I press the max button to turn it on and it seems to adjust a few vents and then it's just fan noise.