Member Since: 16 Mar 2020
Location: Previously Stoke-ST4 (pre-pandemic), Mostly The Hague (NL) partially Lyngby (DK) certainly somewhere
Posts: 160
Are you guys sure that "Farmer Chalk" and "Hardware" have not swapped their avatar image????
This car
matches best with this avatar
ps.: By the way, my FBH only smokes very little during the first start in the morning, then... no smoke at all.
17th Jan 2021 1:43 pm
arb
Member Since: 25 Jan 2019
Location: hampshire
Posts: 29
FBH - my fix experience (so far not fixed)
For the benefit of the group, here's my story. Huge thanks to Robbie and others for your wisdom previous.
(scroll to bottom for current status of the problem - and some questions)
Car/FBH - 2011 3.0 HSE 125K road miles with Thermotop V FBH.
Symptoms:
November/December: Slow warm up, poor cabin heat, no evidence of fbh working
I suspected FBH problem and probably thermostat too.
[edit: cabin heat now good when engine up to temp - topped up coolant and re-bled]
Tackling FBH first...
Diagnosis:
FBH not kicking in on cold (<2C) starts. No smoke, noise or heat from FBH unit.
Ran reader (autel) and found dosing pump issue - (and possibly wiring from reading other posts)
Made up diagnostic cables for Webasto software and plugged in. Same issue - pump.
Found dosing pump, noticed that it had been unplugged (either previous owner or LR(!) when they replaced the tank sender cabling?) - anyways, re connected the pump plug.
Ran Webasto diagnostic again. Pump problem gone. Won't start though (also get "NAK: access denied" error), but other functions working separately (glow, pumps, fan etc - and did the measuring trick for the dosing pump) - so i know that the software is chatting to the unit at least. (using either 2.16.1 or 2.14 versions of the software on com3/usb by the way)
Cleared faults for good measure to start with. (no change - still not working)
Dismantle/clean FBH
Extracted FBH for further examination - connecting the coolant loop and bagging/plugging other connectors in the meantime.
Dismantled FBH - remarkably clean and seals / gaskets in good nick - but diesely / moist. Probably due to priming and non ignition.
Made further dismantle (burner unit) - found cracks in the ceramic. (pics) - but the rest of it (glow plug, 'cup' etc) is in great nick.
From what I understand, these cracks in the ceramic means a whole new burner unit!
Seems like a huge waste (for such a small failed part) - so challenge is finding supply options for a replacement ceramic burner part.
My thinking: Worst case will be new burner unit so nothing to lose in trying.
Solution 1 attempt - salvage sound ceramic from another unit.
Bought this from yeabay (from a 2007 RRS - but still a Themotop V) - (~£60) almost identical to mine.
I figured at least I'll have some further spares to hand that way too!
Dismantled RRS unit - overall in much worse state than mine - sooty and some corrosion; seals & gasket poor condition.
Ceramic burner part looks complete and very close to identical to mine (slightly different 'fin' design)- just a little chip near the glowplug hole - hopefully not a huge issue. But key point - no cracks through it.
VERY carefully extracted the ceramic and part of gasket - tweezers, surgeon's hands etc.
Reinstalled salvaged gasket and ceramic to my burner.
Cleaned up exchanger and all around, and rebuilt with new gasket and o-rings.
Reinstalled to D4 and bled coolant.
===============
TODAY: STILL NOT FIRING (grrr). (Outside temp 8C; coolant temp 8C)
Today's diagnostics:
Webasto software gives me STFL and occasionally error 81h (EOL checksum - whatever that is?)
Checked separate functions (glow, pumps, dosing amount, fan, etc - all still ok)
Still unable to start the unit from webasto software ("NAK: access denied")
Also, from the fault list I get a 112C temp reading? (see screenshot pic) - clearly nothing is 112C - is that a historical stored reading perhaps?
Robbie / Martin / anyone - any ideas? anything i've missed?
Thanks so much in advance. Can't give up now - come so far!
Last edited by arb on 17th Jan 2021 4:07 pm. Edited 1 time in total
17th Jan 2021 1:55 pm
cmb2020
Member Since: 08 Sep 2020
Location: Buckley, North Wales
Posts: 1150
Hi again
Thanks for the reply...
So does it look like the fuel cup is the cause of mine not working? Or?
Tia
17th Jan 2021 2:47 pm
Martin Site Admin and Owner
Member Since: 06 Nov 2004
Location: Hook Norton
Posts: 18557
Looks to me like the dataset (calibration) in the control board is faulty, the EOL error means the data is corrupted (the checksum doesn't match).06 D3 SE / 15 LR D90 XS SW / 88 LR 90 Td5 / 68 BMW 2000 ti
Any issues with the site let me know!
22nd Jan 2021 2:46 pm
arb
Member Since: 25 Jan 2019
Location: hampshire
Posts: 29
Thanks so much for taking a look Martin...
Any idea how might this corruption might be fixed? New board? Software update?
eg. I <could> try swapping the board from the RRS salvage unit (mentioned in post above) into mine?
In the meantime I'll also try another lockout / restart and check some of the other diagnostics I can attend to (eg temp sensor resistance check).
Cheers
22nd Jan 2021 4:08 pm
Robbie
Member Since: 05 Feb 2006
Location: ¯\_(ツ)_/¯
Posts: 17932
The replacement ceramic burner is a different version too, which may not be encompassed by the installed firmware look-up tables.
Given the issue spotted by Martin you could try the replacement board and match it with its original ceramic burner but without the full visibility of the Webasto firmware versions it is impossible to say if it will work or not with your Disco, so a case of try it and see.
Sorry I don't get to the forum much these days - concentrating on staying alive and stuff, but I got your note.
Land Rover - Turning Drivers into Mechanics Since 1948
Member Since: 08 Sep 2020
Location: Buckley, North Wales
Posts: 1150
Ah yeah!
Do you think it would bypass loss of time and money if I made one to test fist? See if it’s even that that’s the problem. Thinking maybe some foil folded and shaped, to last at least one try. Or maybe a sowing finger cup thing.
Don’t want to find after the effort that it’s something else.
Thanks in advance as usual
28th Jan 2021 4:53 pm
Motolab
Member Since: 18 Oct 2019
Location: Sleen
Posts: 1820
MacGyver........
although i like creativity ....... not to much on FBH's its fuel, it burns (sometimes) or better can burn...
go to a webasto service station and let it diagnosed.. if you do not know what to do..
but no-one here can you help now.. since you changed a few parts who are not supposed to be changed
(nozless etc) units from the same year can have different parts/parameters, etc...Best regards
Harold
Always looking for Pre '55's & Pre war British Motorcycles! knowing or having one for sale? PM please. I visit the UK 6 times a year
Ps. I edit my texts quite often, english is not my native language, so I will edit My “typo’s” etc.
28th Jan 2021 5:32 pm
cmb2020
Member Since: 08 Sep 2020
Location: Buckley, North Wales
Posts: 1150
Hiya 😅
No parts have been changed on mine. Just opened and cleaned and took pictures.
Guess I’ll ignore it now until next winter when it’s needed again and I’ve got the money for their service. As I’m presuming it will be another ridiculous bill
Thanks all
29th Jan 2021 4:14 pm
arb
Member Since: 25 Jan 2019
Location: hampshire
Posts: 29
cmb2020 - I feel your pain. Today I had time to test the sensors (all checked out) and tried the board swap from the salvaged RRS unit i bought. Managed to do that with the rest of the unit still plumbed in!
Long story short - IT WORKED. Connected up to WTT software, cleared historical errors (as the board was from the RRS unit) and it fired up perfectly - lots of smoke - as it cleared out probably 5yrs of non use from the exhaust.
Ran it (without NAK errors now) for 5mins. Chickened out and stopped it for a while. Then did a full burn engine on for at least 15mins until the smoke subsided. No errors, Perfect burn. Stopped it, cool down and still no errors.
Frankly I'm elated, as I've been wrestling with this for a couple of months now. Hate giving in.
I'll be writing this up properly incase anyone benefits from it.
Thanks again to Robbie and Martin for their wisdom - without which I'd never have got this far.
PS>
cmb2020, from my experience, I'd suggest you source a salvage unit like I did. find the closest match you can. Of course pot luck if the cup on your salvage is in decent nick. But worth a try I'd say.Best of luck chap.
31st Jan 2021 12:19 am
zinke
Member Since: 22 Feb 2014
Location: Scunthorpe
Posts: 584
cmb2020 I've just posted about the fuel cup. Mine was burnt out, it would start most of the time but was bad for not restarting once it was warm (guessing the time it powered the glow plug is less so it didn't fire).
I replaced the burner and so far its been ok, hot restarts are fine etc but its only been a few days. I had a old heater from a jag kicking about so robbed parts from that, they are the same apart from the software (if you want to use the whole jag unit then just swap the circuit boards over).
Pete.IID, webasto software and workshop facility's available.
2nd Feb 2021 3:00 pm
Robbie
Member Since: 05 Feb 2006
Location: ¯\_(ツ)_/¯
Posts: 17932
arb wrote:
Frankly I'm elated, as I've been wrestling with this for a couple of months now. Hate giving in.
I'll be writing this up properly incase anyone benefits from it.
Thanks again to Robbie and Martin for their wisdom - without which I'd never have got this far.
Well done!
Land Rover - Turning Drivers into Mechanics Since 1948
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