robertofollia
Member Since: 16 Aug 2006
Location: Sometimes over here, and sometimes over there
Posts: 147
  
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| Disco 3 HEVAC codes B1B74, B1B75, B1B76 and B1B77 |
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Hi all
Sorry for such a long post but tried to explain as much and as best as I could.
My Disco3 (V8 4.4 7A MY) has been making us all suffer when the cold weather comes for the last 4 years
-passenger side temp more or less ok
-Driver's side: Feet temp ok, window defroster temp OK, face vent temp close to window OK, driver's right face vent temp f******* cold.
Errors chased, found and cleared every time I check
B1B74, B1B75, B1B76, B1B77
(except for one time that only B1B76 was thrown-blend motor)
It's odd that these codes have been coming for the last 4 years whenever I plugged the reader
If I clear codes, make the system self calibrate itself (key off, depress ECON and recirc and key on), switch off. Restart car and check codes without starting HEVAC, no codes after recalibration
But if I use hevac in AUTO or manual mode, codes show up whenever I check (the 4 of them)
BTW thermostat and battery are new. and cabin filter as well
it's very odd all motors can crap out at once, because distribution flaps (in theory) work . You can feel air distribution changing whenever feet, windscreen or face mode are selected
What I don't want to do is replace all motors at a cost and find the same codes showing up again.
But, could it be there is one vent/blend flap broken or stuck? RAVE states that if some resistance is felt or turning becomes harder an error code is thrown and that blend motor disconnected.
Is there any way to check flaps work, are not stuck or broken?
Can they be oiled/greased/cleaned not having to take the whole heater unit apart (that would involve A/C re gassing?)
When fan is set to full blast not so much air comes out from all vents but there is a lot of noise, so blower is OK) (when the car was new defrost mode sent a blast out of all vents, not like now).
The only cause I can think of is that in 2010, coming down from Italy in a very hot summer my brother decided to use all modes at the same time (face, wind and feet) and since then the amount of air coming from vents at full blast is a shadow of what it used to be.
At that time, still under warranty, the dealer uploaded several software updates to no avail.
And now, it's the no heat from one of the driver's outlets
If I replace motors I will renew heater matrix as a matter of course just in case it's partially clogged.
Don't think it's totally clogged because in that case one side would be ok and the other wrong or both wrong, but not one side partly wrong.
Besides, when HEVAC is off all outlet vents are warm to touch
But being a Land Rover, anyhting is possible. Coolant has been renewed every 2 years since car's build date.
I could try to unclog heater by filling it up with vinegar, let it seat forr 5 days and flush but feel safer with a renewal as it's easier than in a D2.
What else could I look at?
Best regards and thank you
Robert Regards, Robert
Only a closed filling station can prevent me from reaching my destination
1992 Santana 88"SWB petrol
1995 RRClassic 300Tdi
1999 D2 V8 manual coiler
2004 D2 Td5... SOLD!
2006 D3 V8 SE
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 4th Nov 2023 8:16 pm |
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robertofollia
Member Since: 16 Aug 2006
Location: Sometimes over here, and sometimes over there
Posts: 147
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No one in 107?
I made a search prior to posting but nothing came with these codes.
Anyway I have looked at all posts "no heat" related.
The fault codes are weird. I guess the core is partly (not totally) clogged up and there is something wrong with the ECU or motors. When the car was under warranty the stealership uploaded 3 different firmwares to no avail
And self calibrating made a small difference. So I'll try a code clearing, self calibrating, hard reset plus self calibrating again plus de-scaling the core (i'll fill it with coke and let it sit for a night, flush after that and then make circulate vinegar for a day using a fluid pump plugged into the heater pipes with a final flush . Coke declogs and vinegar cleans and removes scale. Does not attack rubber not eats ally pipes. Will report progress (but will be in 1 month time as car is 450 miles from where I live -(with me are RRC and D2)
Best regards Regards, Robert
Only a closed filling station can prevent me from reaching my destination
1992 Santana 88"SWB petrol
1995 RRClassic 300Tdi
1999 D2 V8 manual coiler
2004 D2 Td5... SOLD!
2006 D3 V8 SE
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| 7th Nov 2023 11:15 am |
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Simms
Member Since: 25 Feb 2023
Location: Upper Caldecote
Posts: 19
 
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| Heater matrix - 2 green button hose to pipe connectors |
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Hi
Does anybody know the part number and/or where these can be purchased from ?
The wife’s getting cold and the videos I’ve seen show a possibility of them breaking.
Kind regards
Simms
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| 24th Oct 2024 11:00 am |
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kajtzu
Member Since: 10 Aug 2017
Location: Helsinki
Posts: 6752
 
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Not sure what part you’re after really but https://new.lrcat.com can be used to find it.
If it’s the heater matrix (heater core) that you’re after, Nissens is reputable and sold by many.
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| 24th Oct 2024 4:00 pm |
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Simms
Member Since: 25 Feb 2023
Location: Upper Caldecote
Posts: 19
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Thank you kajtzu, I’ll have a look.
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| 24th Oct 2024 4:34 pm |
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