HVAC heat blows warm/hot on drivers side, cool/cold passenger side (warranty issue)

[Daox]

I am sure that it would fit in there. I don't think it would make it around the 90 degree bends though.

[01-7700]

Tangential but not completely off-topic: Why did the Mirage go to manual HVAC controls instead of the auto climate control that my 2014 has? Cost savings for sure but was there a known problem?

[Eggman]

Tangential but not completely off-topic: Why did the Mirage go to manual HVAC controls instead of the auto climate control that my 2014 has? Cost savings for sure but was there a known problem?

If responses on this message board 1.) have any influence and 2.) are any indication my guess is demand rather than reliability. I don't read about many failures here on the auto climate controls.

Someone please correct me if I'm wrong here.

[pilchardfish]

Hey guys. Just to chip into this thread (and there are 12 pages of it so apologies if someone has posted this already).

I've just popped to my dealer as I have this issue - and I'd found this thread the other day too. Being the UK (drivers side is right hand side) it's blowing cold on the right of the car, warm in the middle, and piping hot on the left.

I mentioned this to the dealer and apparently there's a known manufacturing fault with the heater matrix in the Mirage on some model years. It's a gradual thing that usually shows up relatively quickly if it's going to. Excuse my terminology as I neither know what this part looks like and I may not be relaying what the dealer said exactly; but apparently the heater sucks air through the matrix; over time, the way it's designed (there's some sort of support on it apparently), means that the metal furrs up somehow (to use their term) reducing the heater performance. It always shows the same way - right hand side gets cold, left hand side stays hot. By furrs up, I don't think they meant fluff, possibly that the metal reacts.

Apparently they've done loads of them under warranty; it's a several hour job and needs the dashboard to come out, stuff to be drained, and a new heater matrix installed.

I realise many of you on here are mechanics (or handy!) and are trying to solve the problem; but it seems to me the answer is simply a faulty part that needs replacing. Thankfully, I'm 2.5 years into a 5 year warranty, so I've no worries on that front, and happy to let the dealer just sort it.

I also asked if they solved the issue; and apparently Mitsubishi changed how the matrix was manufactured to stop the issue from recurring. So once the part is replaced, it shouldn't be an issue that comes back, and it's not an issue seen on facelifted Mirages; just the first generation as a rule.

Hope that helps someone and narrows the fault away from discussion of actuators, flaps, cleaning the system out with corrosive chemicals, etc.

[pilchardfish]

If responses on this message board 1.) have any influence and 2.) are any indication my guess is demand rather than reliability. I don't read about many failures here on the auto climate controls.

Someone please correct me if I'm wrong here.

In the UK they used to sell three models; a basic one with no frills and no AC; a mid range one with manual controls and AC; and a top of the range one with auto climate controls. I believe sales of the mid and bottom tier car were low; with most people buying the top of the range one. I guess people didn't want to drive around in a basic car with no mod cons. So they now just sell one single model of Mirage in the UK with all the bells and whistles attached including the climate control. Each market will be different. For example when I bought my 2015 Mirage, you couldn't get heated seats, multimedia radio, cruise control, etc. But that is now standard. However in Australia, from day one, they sold a version of the Mirage with all of those things and more. So yeah, each market is different, and I don't think anything to do with reliability.

That said; MMUK did stop fitting front and rear parking sensors; they're a nightmare - going off for no reason sometimes! They replaced it on mine under warranty, but from what I gather, loads of folks had bother as it's just an aftermarket thing MMUK put on in the docks when they arrive from Thailand. (Off topic sorry haha)

[Top_Fuel]

...just popped to my dealer as I have this issue
...Being the UK (drivers side is right hand side) it's blowing cold on the right of the car, warm in the middle, and piping hot on the left.

With a right-hand drive Mirage, the driver would notice this issue immediately. I rarely have a passenger so I may never realize that my right side vent is blowing colder air.

...apparently there's a known manufacturing fault with the heater matrix in the Mirage on some model years.
...they've done loads of them under warranty
...it's a several hour job and needs the dashboard to come out, stuff to be drained, and a new heater matrix installed.

Wow...that's huge news!

This would be an expensive repair...probably close to $2,000 US. The auto climate control heater box is something like $1000. Maybe 6 hours of labor, anti-freeze, shop supplies...etc.

I wonder if there's a Technical Service Bulletin describing this issue in any non-US market?

[Daox]

That is hugely helpful Pilchardfish! Thank you for posting that information. Now we know what the issues is, and we'll just have to come up with our own solution (for those of us not under warranty).

I agree, seeing a TSB or something would also be very helpful. Did you get any documentation with your warranty work that may be helpful to us?

[Fummins]

I assume the heater matrix is the heater core?
For those without warranty: http://www.rockauto.com/en/catalog/m...ater+core,6864

I assume it must be enough of a common issue. If not I highly doubt any aftermarket mfg would bother making a heater core that only fits the Mirage. Especially seeing as there isn't much for shocks or struts yet.

[Top_Fuel]

I assume the heater matrix is the heater core?

Oh...you know I think I read his post the wrong way. I thought the heater matrix was the entire heater box assembly?!? If it's just the heater core, that would make more sense.

I think I'm going to insert 2 thermometers in my 2 round dash vents and start monitoring this more closely. I will definitely want to document this with the dealer before my bumper-to-bumper warranty is up. I wonder if the replacement unit will be any better?

[Daox]

I'm thinking the heater matrix is the airbox that has the flappers and holds the heater core, evaporator, and PTC heater.