Repeat Heater core Failure

Forum for Infiniti M37, M56 M35h Hybrid and Q70 owners.
FilltheFetters
Posts: 4
Joined: Sun Mar 11, 2018 7:04 pm
Car: 2012 M35h

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I bought a 2012 Infiniti m35h just short of two years ago, on the original test drive I noticed there was no heat coming from the vents even when set to the max temp and fan speed. The dealership looked into and decided the heater core needed to be replaced and did so to the tune of roughly $2000 Canadian. 2 years later and only about 13000kms more on the odometer and I am having the same issue, brought it to another dealership and they said the heater core needs to be replaced again or potentially they could try and replace the automatic transmission fluid warmer. Just before buying this car I looked at another of the same model and it also needed a new heater core according to a third Infiniti dealership in my area. I am wondering if anyone else out there has had to replace theirs or had a reoccurring issue with it. I do not want to go ahead and replace it again because there seems to be a underlying and unresolved issue and I am worried it will fail a third time shortly afterwards.


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Ilya
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Car: 2011 M56x but I spend a lot of time on my 2015 Kawasaki Vulcan S. Former owner of a 2007 M35x. Also take care of my wife's 2016 QX60.
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Welcome!

Is the original dealer still around? I would go to them and see if they will warranty it...heater cores do go bad, but not that soon. Most take nearly 10 years and 150kmi to go bad (give or take depending on use - just using a large number for emphasis). I would also consider calling Infiniti Canada...they may be able to help with the repair as this is definitely far too soon for it too fail.

FilltheFetters
Posts: 4
Joined: Sun Mar 11, 2018 7:04 pm
Car: 2012 M35h

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The original dealer is still around just further away and in a larger city, so I went to the local dealership with the expectation that any sort of warranty/goodwill work would be funded by Infiniti not the specific dealership, but At this point I intend to visit the dealership that installed the part. I am not all that optimistic after my last visit, they noted an unusual amount of debris in the coolant but could not suggest a source, and they also implied a new heater core would be a guaranteed solution whereas replacing the automatic transmission fluid warmer instead could fix it as well but with less certainty. I could not follow their reasoning at the time as the last heater core failed so quickly, it seemed like they were guaranteeing their profit margins and not actually solving the problem.

You will have to forgive my ignorance on this, while looking for the sediment I noticed the coolant in my reservoir appeared to be quite turbulent. I can't say I have paid much attention to it before but it caught my eye and I can't seem find a answer elsewhere online.

https://imgur.com/a/PFlKHqJ

Is this to be expected? Are there multiple connections to a reservoir and if so does coolant usually flow through the tank and/or would this just be caused by vibrations from the engine idling? I looked at a couple of our other vehicles while they idled and the coolant appears to be still by comparison.

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Ilya
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Posts: 9800
Joined: Fri Apr 23, 2010 11:20 pm
Car: 2011 M56x but I spend a lot of time on my 2015 Kawasaki Vulcan S. Former owner of a 2007 M35x. Also take care of my wife's 2016 QX60.
Location: Charlotte, NC
Contact:

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@EdBwoy, you have more experience in this department than I. That does look a bit more turbulent than what I'd expect...but truth be told I've never watched my overflow tank while the car was running so don't know.

I agree with you that any Infiniti dealership should be able to take care of the issue of another Infiniti dealership and take it up with corporate but...that doesn't always happen. Hence why I said call Infiniti Canada, create a case # and have that attached to any work. That way, any dealer may be more willing to assist as the issue is backed by Infiniti HQ.

thonings90
Posts: 2
Joined: Tue May 21, 2019 3:08 pm
Car: 2004 Infiniti Q45 Premium
2012 Infiniti M35h

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FilltheFetters wrote:
Sun Jan 19, 2020 10:48 pm
The original dealer is still around just further away and in a larger city, so I went to the local dealership with the expectation that any sort of warranty/goodwill work would be funded by Infiniti not the specific dealership, but At this point I intend to visit the dealership that installed the part. I am not all that optimistic after my last visit, they noted an unusual amount of debris in the coolant but could not suggest a source, and they also implied a new heater core would be a guaranteed solution whereas replacing the automatic transmission fluid warmer instead could fix it as well but with less certainty. I could not follow their reasoning at the time as the last heater core failed so quickly, it seemed like they were guaranteeing their profit margins and not actually solving the problem.

You will have to forgive my ignorance on this, while looking for the sediment I noticed the coolant in my reservoir appeared to be quite turbulent. I can't say I have paid much attention to it before but it caught my eye and I can't seem find a answer elsewhere online.

https://imgur.com/a/PFlKHqJ

Is this to be expected? Are there multiple connections to a reservoir and if so does coolant usually flow through the tank and/or would this just be caused by vibrations from the engine idling? I looked at a couple of our other vehicles while they idled and the coolant appears to be still by comparison.
That video is showing the inverter cooling fluid for the hybrid system. Mine does the same thing and the dealer tells me it’s normal. Currently my M hybrid is in getting the heater core replaced, for the first time at 64k miles. Should I be saving for this repair again or would regular flushes help?

FilltheFetters
Posts: 4
Joined: Sun Mar 11, 2018 7:04 pm
Car: 2012 M35h

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The first time it they replaced it for this car was at 55k kms and they claim it needs to be done again at 68k kms. Yours appears to have lasted about twice as long as the original in my car. Not sure if there is some regular maintenance to avoid this problem.

sadboy
Posts: 32
Joined: Sun Jan 19, 2020 8:39 am
Car: 2012 M35H

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This scares me as I just had the heater core replaced on my M35H and have had blend door issues ever since. A repeat heater core failure would be severely disappointing.


Are you sure the first heater core install followed the Infiniti TSB procedure on it? It involves bleeding the system and replacing the thermostat.

Maybe they messed something up while replacing it?

sadboy
Posts: 32
Joined: Sun Jan 19, 2020 8:39 am
Car: 2012 M35H

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thonings90 wrote:
Mon Jan 20, 2020 8:28 pm
FilltheFetters wrote:
Sun Jan 19, 2020 10:48 pm
The original dealer is still around just further away and in a larger city, so I went to the local dealership with the expectation that any sort of warranty/goodwill work would be funded by Infiniti not the specific dealership, but At this point I intend to visit the dealership that installed the part. I am not all that optimistic after my last visit, they noted an unusual amount of debris in the coolant but could not suggest a source, and they also implied a new heater core would be a guaranteed solution whereas replacing the automatic transmission fluid warmer instead could fix it as well but with less certainty. I could not follow their reasoning at the time as the last heater core failed so quickly, it seemed like they were guaranteeing their profit margins and not actually solving the problem.

You will have to forgive my ignorance on this, while looking for the sediment I noticed the coolant in my reservoir appeared to be quite turbulent. I can't say I have paid much attention to it before but it caught my eye and I can't seem find a answer elsewhere online.

https://imgur.com/a/PFlKHqJ

Is this to be expected? Are there multiple connections to a reservoir and if so does coolant usually flow through the tank and/or would this just be caused by vibrations from the engine idling? I looked at a couple of our other vehicles while they idled and the coolant appears to be still by comparison.
That video is showing the inverter cooling fluid for the hybrid system. Mine does the same thing and the dealer tells me it’s normal. Currently my M hybrid is in getting the heater core replaced, for the first time at 64k miles. Should I be saving for this repair again or would regular flushes help?


I thought the same thing when I saw my coolant vibrating. The part that concerns me the most is the fact that people have repeat instances of heater core failure?

What on Gods Green Earth is Infiniti up to? That would be embarrassing as its almost a 3000$ job.

Preventative maintenance would keep me sane. Waiting for an Infiniti Tech who has had experience with these to chime in.

Davealan
Posts: 57
Joined: Sat Apr 29, 2017 5:15 pm
Car: 2012 M Hybrid Black Obsidian & graphite w/ Deluxe Touring package

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Gents, I bought a used 2012 M35H back in 2016 from a wholesaler during the summer while living in Norfolk, VA and I thought I had the best car ever until the winter came... Plenty of my posts about the "too good to be true" M35H purchase.

I spent hours researching the heating problem, having the issue diagnosed, getting quotes and talking with Infiniti USA. No solution other than to pay $3,000 and I won't do it.

Each winter since I have weathered the cold by dressing in layers, using the heated steering wheel and heated seats. Now living in Nashville so not the coldest winters. I get some residual heat out of the system on the driver's side only so I close the vents on the passenger side October on.

This is a major design failure by Infiniti and they have ripped us all off.

Apart from the heat issue just the typical issues until recently when I noticed the LCD panel on the cluster has gone dim even when at the highest brightness setting. Looking forward to any eventual non Infiniti. replacement.

FilltheFetters
Posts: 4
Joined: Sun Mar 11, 2018 7:04 pm
Car: 2012 M35h

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I ended up bringing the car back to the dealership that replaced the heater core before I had purchased it. A mechanic there called after looking at it and was surprised to see it in again for the same problem, supposedly they ended up covering some of the man hours but at the end of the day they had it "fixed" at a cost of $1000 Canadian. They brought in someone from a company that sells solvents to flush radiators. They tried a couple solutions and were able to backflush the sludge that was clogging the heater core. It is still working as far as I am aware but won't really know until winter again. The mechanic suggested flushing the coolant with every oil change which speaks to the suggested longevity of this fix. Not sure why they cannot come up with a long term solution or find the actual source of the problem.
I came across a post on reddit about someone installing a wix coolant filter to their vehicle and wondered if that might be a better solution to add inline with the heater core. I suspect this would be cheaper than flushing all the coolant every oil change. Does anyone know if this would be a reasonable idea to try out? I will link what they used.

Heavy Duty Filter Mounting Base
https://www.amazon.com/dp/B0014BJYYW/re ... a_aw_od_pi
WIX Filters - 24069 Heavy Duty Coolant Spin-On Filter
https://www.amazon.com/dp/B0014B8S8A/re ... a_aw_od_pi

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VStar650CL
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Joined: Thu Nov 12, 2020 1:25 pm
Car: 2013 Nissan Altima 2.5 SL
2004 Nissan Altima 2.5 S

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FilltheFetters wrote:
Sun Jul 18, 2021 1:35 pm
I came across a post on reddit about someone installing a wix coolant filter to their vehicle and wondered if that might be a better solution to add inline with the heater core. I suspect this would be cheaper than flushing all the coolant every oil change. Does anyone know if this would be a reasonable idea to try out? I will link what they used.
I've only seen them on a few diesels, but I can't imagine it would hurt anything to try it. My question would be, why are the cores clogging in the first place? The reason we see far fewer clogged cores than the old days is that there's no heater control valve on modern cars to stop the flow and allow crud in the core to ossify over the summer. So it seems unlikely to me that chronic clogging could be from particulates settling out in the core. It seems more likely to me that there's some chemical or electrolytic process going on with the core materials that's causing internal corrosion. If one of y'all get a core replaced, ask for the old part and give it a bandsaw job, I'd love to see some pics and they might tell a story. One thing you might consider trying is a sacrificial marine zinc someplace in the cooling system. They sell zinc "fingers" that you can adapt to the drain plug and I've installed a few over the years for people with unexplained corrosion issues. Nothing complicated about it other than routing a ground wire to the finger once you modify the plug.


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