Tap, tap, tap when the fan is on!

[wadjssd]

Hi there,

I've got a persistent tapping sound when my fan is on. Not the aircon, just the blower.
The tap is very uniform and steady, and stops as soon as I kill the blower. From the driver's seat, it's coming from somewhere over on the passenger side, quite low down, and sounds almost like it's under the footwell.
This morning, I left the engine idling and went around to the outside of the car, and it was clearly audible from outside too - low down around the front passenger door area.

Any ideas what could be causing this? I know there's an auxiliary heater housed somewhere, but no idea if this could be the culprit or not. The problem persists even when the engine is fully up to temperature and so the aux heater shouldn't be required.

Thanks
Andy

[StephenVA]

Probably the blower motor bushing going bad. Mine squeaks very quietly when cold but goes away after 5 mins of drive time never to be heard from again until morning.
Solutions: Ignore or pull and relube bushing (?!)
End Results: It will get worse then die.

Recommendation: lay on passenger floor to pin point location. Attempt to pull blower motor and inspect for interference or slack in parts sounding it. I have no experience in this area on an X5. Most are a PITA.

[upallnight]

could be something got suck into the blower motor and is now hitting the fan as the fan turns.

[bmwfanx5]

Its the auxiliary heater making a ticking noise when on in cold weather to aid heating interior, when you turn the fan off it is not required so stops.

[wpoll]

Originally Posted by bmwfanx5

Its the auxiliary heater making a ticking noise when on in cold weather to aid heating interior, when you turn the fan off it is not required so stops.

The aux. heater runs if you start the car at an ambient temp of less than 6DegC. (i.e. 5.5DegC. or lower) and heats the engine coolant until the engine coolant reaches 75DegC. - it then shuts off. It uses the aux. water pump to distribute warm water to the engine. It is not coupled to the blower motor on or off status directly but if you shut down the blower completely and that shuts off the IHKA unit entirely, that might kill the aux. heater. I never turn my IHKA off so I'm not sure.

I wouldn't test this too much either. Once the aux heater starts, it's a good idea to let it run at least 3 or 4 minutes and get up to operating temp. Short runs and frequent on/off cycling will lead to a fouled Webasto (aux. heater unit) that can be hard to repair

I have the "Telestart" remote (a copy actually) and can start the aux. heater manually. In this case (engine not running) the IHKA will monitor the coolant temp and when it gets to about 30DegC. the IHKA will start the blower motor, set the vents to "screen" and start to warm the screen and cabin.

BTW, the aux. heater doesn't make a ticking sound - it's the fuel dosage pump feeding the aux. heater that makes a ticking sound - the aux. heater sounds like a small jet engine and doesn't actually tick itself.

If it's a foreign object hitting the blower fan blades, the ticking sound will change rate with fan/blower speed changes.

[Danny2121]

Hi Wpoll,
I have the same issue as above.
It’s very frustrating it’s being making the intermittent noise for a while now, first I thought it was the exhaust back firing.
Until I turned the blowers off it stopped, then turned them back on it stated again so I knew it was something linked to the blowers when operating.
Do you know where the fuel dosage pump is situated and how to test if it’s definitely this?
Thank you in advance.
Danny

[wpoll]

Originally Posted by Danny2121

Hi Wpoll,
I have the same issue as above.
It’s very frustrating it’s being making the intermittent noise for a while now, first I thought it was the exhaust back firing.
Until I turned the blowers off it stopped, then turned them back on it stated again so I knew it was something linked to the blowers when operating.
Do you know where the fuel dosage pump is situated and how to test if it’s definitely this?
Thank you in advance.
Danny

First question - is the outside (ambient) temp below 6 Deg.C ? If not, then the Webasto heater should not be running.

Second question - is the Webasto heater running when you hear the ticking sound?

The Webasto heater fuel pump is under the left-middle of the car and can be clearly heard when its running - you can hear the ticking (just) over the heater exhaust in this video clip @ 03'35"

https://youtu.be/trPWg1arWFg

You can see the Webasto fuel pump in it natural environment in this video @ 00'35" - it's the middle unit with brass fittings.



https://youtu.be/bGj92asy9U8

HTH...