Hi,

I'm hunting for the source of a slight but annoying whirring fan noise on my 2012 4.4 TDV8 (LHD). It sounds like a smallish fan with failing bearings, not like something big like the HVAC blower. It appears to be adjusted in speed frequently because the noise changes in pitch every few seconds and sometimes stops then comes back. So far it has only appeared with the engine running.

My first guess was the temperature sensor intake fan behind the small grille in the climate control unit. But myself and a passenger heard it coming more from the fuse panel behind the lower glove box. Then I discovered that I am also able to hear it from the outside, clearly coming from the depths of battery compartment or perhaps somewhere behind the pollon filter housing.

That led me to suspect the ECU fan depicted in the parts catalogue (https://parts.jaguarlandroverclassic.com/parts/index/part/id/21.9I.9I3.9I30314.9I3031405A/brand/land-rover/) as well as workshop manual. Problem is: I don't have that fan nor cowling on my ECU nor can I find the power connector on the ECU loom. That spawns an independent question: Have there been 4.4 TDV8 with that fan but omitted on some/later models or am I actually missing an ECU fan? At least some 2011 models seem to have had it: https://www.landyzone.co.uk/land-rover/mys...t-4650620.

I found quite some reports of an e-box fan causing similar symptoms on 3.6 models but on the 4.4 TDV8 the whole arrangement seems to be different and I don't seem to have that fan either.

What other likely candidates are there? Should I go looking behind the glove box or rather in the depths of the battery box and HVAC intake? Could it be something completely different like the final stage resistor or related parts causing an electric frequency humm rather than a fan (would need to be quite extreme though to explain the sound)?

Thanks in advance,
Michael

Its a long shot but has your car got the Deisel parking heater fitted?

The heater is located behind the front passenger wheel and automatically comes on to assist heating the engine up when cold, this sounds like a fan with worn bearings sometimes when its running 2012 TDV8 Autobiography Baltic Blue
Previous
2007 BMW M5 E60

Hey colalowe,

spot on! I had the same hunch today and switched on the fuel burning heater via the fob and within seconds that annoying whirr appeared. After switching the FBH off, the whirr went on for about 20 seconds and then went away for good. This corresponds with my recollection that previously it appeared after starting the engine in colder weather (< 10 deg.C.). For the last few days it was warmer so I didn't hear it. For some reason it also came on at least once as I remember quite some time into a drive when the engine should have been warm already. I'll continue to observe.

Does the FBH actually have a fan or some other part that could be worn to make that noise or is it just the normal operating sound and I'll have to live with it? (Now that I know what it is I maybe even could.)

Thanks!
Michael

Hi Michael

the heater does have a fan inside it, and they do have that noise as far as I'm aware, I tend not to notice mine so much although If I listen for it, I can hear it when it is running.

Here is a video of one running on Youtube, its a bit louder as the camera is by the exhaust but you can hear the fan ramp up and slow down as it goes through the cycle.

 2012 TDV8 Autobiography Baltic Blue
Previous
2007 BMW M5 E60

Hi colalowe,

thanks for the video. Good to have a baseline to compare against. The sound I get is different from all those in the video, subjectively louder, maybe because it's less static (changes pitch) and therefore more annoying - a proper "fan on it's way out" whirr.

I just tried to reproduce it in the parked car with ignition off using the fob. But apart from a short whirr sounding like a pump priming it didn't seem to fire at all. What did come on was the interior fan at full blast but after 2 minutes still no warm air nor any of the heater sounds from the video (reading the workshop manual now, maybe I was not patient enough).

Here's part of a video I recorded: https://dinsnail.net/~michael/ffbh.mp4

The whirr I got for minutes on end was like a continuous repetition (at changing pitches) of the short priming-like noise you can hear directly after my pressing the ON button on the fob. (not the vent flaps adjusting after that) Maybe the heater on it's way out tried to prime/fire/spin-up continuously and has now fully given out or gone into error lockout mode.

I'll try to reproduce once more on the next drive to see if the engine running changes anything.

I just now read in the workshop manual that the actual fuel pump for the FFBH is located in the back of the car inbetween the tank and the spare wheel well. So what I hear it can't be that pump priming the actual fuel.

Seems either way (fan whirr continuing or heater now fully broken) I need to dig into diagnosing what's up with it. I have to admit I have yet to fully read and understand everything the workshop manual has to say about it.

Last I checked I had no fault codes regarding the heater anywhere. I'll recheck.

The workshop manual talks about the ATC (Automatic Temperature Control) module storing codes from the FFBH unit and shows a picture of the climate control unit in the centre console for it. My diagnostics do show an ATCM but mean the terrain response system by it. The HVAC module as the next best thing does not (or at least did not) report any fault codes. (Actually the whole car really only has the ubiquitous EGR inlet temperature sensor fault.)

From what I understand, the ATC module in turn talks to the FFBH control unit using a dedicated K line, which would mean there's no direct access to the FFBH control unit apart from maybe directly attaching some Webasto-proprietary diagnostics tools. As a last resort I guess I could farm this out to a Bosch Service we have one town over who specialise in this kind of thing and do have those diagnostics. But I'd really like to figure this out myself before resorting to that.

Thanks so far,
Michael

Hi Michael

when I had issues with my heater I ended up buying the diagnostic cable for it, it is a pain to get to the heater to plug it in but I found on mine that the diagnostics could run all the individual areas of the heater and confirm they were working but it still wouldn't fire and run on its own.
Where mine was faulty was with the fuel pump, although this was clicking (giving the impression it was working) when I took off the fuel delivery hose at the heater end I found that the pump wasn't actually pumping any fuel to the heater.

I changed the fuel pump and cleared any faults on the heater and it fired up straight away and has been perfect ever since. 2012 TDV8 Autobiography Baltic Blue
Previous
2007 BMW M5 E60

Hello colalowe,

thanks for all your tips. Those diagnostics cables are a lot cheaper than I expected. I've got one on the way now and will try to dig into the FFBH directly.

No error codes in the HVAC module, unfortunately.

I tried starting the heater today using the fob whilst the engine was idling. It did prime whatever it primes for a bit longer (~ 15 seconds) but still didn't seem to fire. But now I'm almost 100% positive that this sound is what I was hearning and searching the cause of. Insofar: Success!

All this made me remember that the burner must have worked of a sort shortly after I bought the car because I remember the typical operational noises I know now from your video and remember it putting out quite a bit of smoke. I didn't think anything more of it but it may have been one of the first symptoms of whatever is going on.

Will keep you posted,
Michael

FBH will not fire up from the fob when engine idling. First what you can do just wait for outside temperature going under +5° and just start cold engine. Webasto should fire up automatically and continue working (if its not in lock mode due several unsucessiful starts). If its working then you can be sure that Webasto it self is ok. The problem in this case is or in circulation pump, or in HVAC. HVAC is very fussy and not let Webasto fire up from the fob for many reasons, for example too short distance traveled last time, too low battery, some own fault ect...and it just not give start permit via K-line and not inform you about this desigion anyhow.
Just start the engine and keep your hand under Webasto exhaust pipe. You must feel the air flow right away. If Webasto working properly, air flow going hot soon. If its not going hot, there is some issue with fuel or fire up. If no air flow at all, then there is some electrical issue inside Webasto and need to read fault codes. Or its in lock mode.
The electrical pump. It may not show any fault codes due electric circuit is ok even when it actially not pumping. Webasto go hot and go into lets say sleeping mode in this case, it think hot water is enough and need to shut down and wait. This is normal operation mode. When the engine is running, there is water flow anyway and Webasto continue running even with faulty water pump.
Also with engine cold start there is 100% sure the HVAC dont have any low battery issue and give start command to Webasto.
Diagnostic. K-line is pin 2 on Webasto and its coming direct to Climate Control. Need just open CC and find this wire: https://www.google.com/search?q=range+rove...bmJsYi5boA

Hallo jaguar3,

thanks! This morning the FFBH fired up and worked on a cold engine start with the dash showing 8 deg.C. outside temperature. Standing outside next to the passenger side fender I heard the turbine-like operating sounds as in the video colalowe linked. I also felt the warm exhaust gas from the FFBH exhaust below the vehicle. I forgot to check interior heating but I noticed how the engine coolant temperature climbed very quickly.

I also heard the annoying fan whirr again both inside and outside the car. My best guess for now is that the FFBH combustion air fan is on its way out. (Maybe apart from the noise this sometimes causes the heater not to fire correctly.)

Next order of business would be to remove the fender lining to have a look at the thing and confirm it is that fan making the noise. Hopefully I could also do some simple checks like the air inlet filter. At the very least I would like to confirm the actual model before I try and order some replacemet parts. As the diagnostic cable arrives I will hopefully be able to confirm and narrow this down further and maybe determine if the dying fan caused additional problems.

Thanks for the tip of using the K-line at the climate control unit end. I'll be certain to look into that.

Thanks,
Michael

Well, hard to say without hearing this noise. Some people wondering even with normal operating noise of FFBH. But its quite common problem with combustion fan, blower just touch the body during spinning and produce additional noise due that. And there is no fault codes with this issue due control module dont care about any noises when circuit is ok.
If you have to change some parts, its just ordinary Thermo Top C there, only difference is control module, its made for communicating with Climate Control. All other parts fits from regular TTC.

Wrong link I send in last post, this one is correct:

&ab_channel=RR

White-red wire.

mxpUz6Q in your video I can see, that yours is in venting mode not in heating mode, so the FBH is not activated (lower LED on AUTO-button blinking). It means that ambient temp is over 15C or at least ECU thinks so.

Anyway did you diagnose the Webasto? Have you sorted out your problem?

Hello kokamagi,

sorry for falling silent - somehow I wasn't notified of your response.

I've been using the car normally and over time have become quite certain now that my FFBH works and is the source of the annoying sound.

I have the fan unit on standby for a changeover to see if that clears it.

But before I take the whole FFBH unit out I wanted to have a look at any error codes and run a manual diagnostic cycle to be certain that firing up the heater also produces the telltale noise. So I went and got the diagnostic cable and software.

As I did want to follow jaguar3's suggestion of using the K-Line from the climate control module to the FFBH but did not want to mess with the original wiring harness, I ordered some parts to put together a 1:1 extension cable with a take-off for the K-Line. The last bits finally arrived this week and I set to work. This evening I tried it all in the car but couldn't get a connection to the FFBH. So I'm now double-checking everything and will give it another go over the weekend.

Click image to enlarge

I found it easier to take K-bus signal from the connector C2242 in the passenger footwell. No need to unplug it (it is unplugged for other reasons in the picture), just back-probed the wire 50 (thin white-red) on the connector. Worked very well.

Click image to enlarge

Hi kokamagi, jaguar3, colalowe,

Good things come to those who wait. So I finally got into the FFBH today. The solution was simply to select the right protocol (Thermo Top BMW or Thermo Top C/Z BMW depending on the software version) which I spotted reviewing the diag video linked by jaguar3 and the Disco3 wiki.

It had only one error logged which might as well have been from my trying to connect with the wrong protocol:

Yes, you need to remove Webasto compleately, there is no space, so its impossible to do it without disconnecting the hoses and remove it compleatly. Its quite tedious work to get it back in place due limited space. Yes, there is normal hose clamps. Anyway you need to replace the gasket due this work, so its better to do when Webasto is on the table.
Also use hose smashing tools (to avoid too much coolant come out).
Air bleeding: there is no any special procedure for that, but dont do it by starting Webasto from the fob (changeover valve saty closed in this case and not let the fluid inside the small circuit). Just start the engine, turn temp. control buttons to max and let it run or a while.