Heater problem

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p15353
Posts: 5
Joined: Tue Jan 05, 2021 6:21 pm
Qashqai Model: Mk.1 Qashqai - J10 (2006–2013)

Post by p15353 »

Hi all

I was hoping some experienced people here might be able to help me

In cabin heating in my 2009 QQ+@ is very poor.

Feed pipe to heater core in cabin gets good and hot. Outlet pipe also gets hot but run fan on medium and 30 seconds later it is as good as cold. Hard to believe it its pulling heat from the core that fast but seems to be doing so.

This is what i have done

1. Replaced thermostat
2. Did the self diagnostics via the heater control panel which showed bad sunload sensor......replaced sunload sensor (no other fault eg all doors, other sensors show clear)
3. Replaced heater control panel (dual with AC) with one from another car to see if that was problem, it wasnt.
4. Flushed heater core with garden hose, both directions.
5. Tried the overnight vinegar fill of heater core, flushed again and refitted....no difference

Driving me cracked at this stage.

I notice there is a joint in feed from thermostat to heater core (see attached). Does anyone know what that yellow bit of plastic is? Wondering if potentially restrictive of flow

Im now beginning to think I will have to replace the blasted heater core to outrule that? No clips on pipe going joining heater core in cabin so hoping this doenst mean dash out (if it does it'll be the dremel, pipes cut, and new install with hoses!)

Thanks a lot everyone. Hoping for some inspiration

IMG_8334.jpg

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calnorth
Posts: 2719
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Qashqai Model: Mk.2 Qashqai Facelift - J11b (2017–2021)

Post by calnorth »

I'm not familiar with the contents of this a/c and heater unit. Don't know what the yellow thing is.

Looking at the diagnostics (see page HAC 111) it certainly points at the heater core when diagnostic steps are completed?

Attached is the diagnostic document...it may not be 100% correct since its for the US vehicles. Can you step through the procedure at page HAC-111. Think you have done some of it?

....................
hac.pdf
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Mk2 Qashqai Facelift - J11b (2017–and onward)
1.6 Dig-T N-Connecta
DaveBerlin
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Location: Berlin, Germany
Qashqai Model: Mk.2 Qashqai Facelift - J11b (2017–2021)

Post by DaveBerlin »

p15353, welcome to the QQ Forum !
Regarding your question on the “Yellow” Part. This looks to me like a Connector Pipe Fitting which joins the two Pipe Diameters together (see Pic). The Black / Green Parts are the Pipe Tube Clamps - I hope this is of help Dave 😉

CD7F39AE-B1E9-41B9-B11B-186A6908F2AA.jpeg

F1C1A0EA-9F65-42D2-9B28-0D33E1B59C0C.jpeg

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gloucester
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Location: Gloucestershire, England
Qashqai Model: Mk.2 Qashqai - J11 (2013–2017)

Post by gloucester »

Welcome to this forum.
(2015 Nissan Qashqai Tekna DIG-T 1.2 sold 15/6/18) ~ 2018 Suzuki Ignis SZ5 - 2018 Yamaha MT-07 ~ (2024 Volvo EX30 ordered)
p15353
Posts: 5
Joined: Tue Jan 05, 2021 6:21 pm
Qashqai Model: Mk.1 Qashqai - J10 (2006–2013)

Post by p15353 »

Thank you @Calnorth. yes, i have ran through the diagnostics and its suggesting heater core alright. The manual suggests that the pipes at the heater core side have clips that can be removed....sadly it doesnt.......(see attached).

Has anyone replaced a heater core like this before? I've read that dash may need to come out....having done that in a car in the past, I aint going there again :) Anyone replaced this with dash in etc?

Great detective work Dave....that's reassuring that it is just a connector ....so that cant be the problem!

Untitled.jpg

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calnorth
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Qashqai Model: Mk.2 Qashqai Facelift - J11b (2017–2021)

Post by calnorth »

If water flow thru the core is pretty much ok the only block I could see would be the Air Mix door(s) which are on the LAN Data Lines (Page HAC 101) and controlled from Auto Amp (HAC 15). Shouldn't think those doors are accessible?

Since operations on modern vehicles is aimed at Production I think service maintenance/repair access is bottom of the list.
Mk2 Qashqai Facelift - J11b (2017–and onward)
1.6 Dig-T N-Connecta
p15353
Posts: 5
Joined: Tue Jan 05, 2021 6:21 pm
Qashqai Model: Mk.1 Qashqai - J10 (2006–2013)

Post by p15353 »

Thanks Calnorth again. Ive confirmed that the air mix door motors are working and I dont get an error code on auto amp self diagnostics to tell me that the door is faulty (so Im working on premise that that is ok)
lewisbryant
Posts: 336
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Qashqai Model: Mk.3 Qashqai - J12 (2021+) New Model

Post by lewisbryant »

Do you have good flow in the system? Possibly waterpump, check flow back to expansion tank at idle and fast idle
p15353
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Joined: Tue Jan 05, 2021 6:21 pm
Qashqai Model: Mk.1 Qashqai - J10 (2006–2013)

Post by p15353 »

Hi Lewisbryant, new waterpump fitted with T/belt last month
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calnorth
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Qashqai Model: Mk.2 Qashqai Facelift - J11b (2017–2021)

Post by calnorth »

p15353 wrote: Mon Jan 11, 2021 4:24 pm Hi Lewisbryant, new waterpump fitted with T/belt last month
I can't see that the blower can make the water flow near cold unless its getting seriously restricted, meaning flow has ceased. This is akin to an airlock problem as well as debris?

Did you use full water main pressure to blow through the core. And did you try that at a lower flow rate?
Mk2 Qashqai Facelift - J11b (2017–and onward)
1.6 Dig-T N-Connecta
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