Failed Heater Core - FOUR TIMES

[bradlogan]

Hello,
New to forum, desperate for some insight.
I have a 2016 1500, Hemi 5.7. I bought it in 2020. Purchased with about 115,00 KM / 71,000 miles. it has 240,000km/ 149,000miles. The truck and I are in a love/hate relationship. Here is the latest issue. yesterday, the heater core has failed for the FOURTH TIME since January 2023. yup, less than 6 months. my local garage has dealt with it each time (they have just a hate relationship with my truck). background. my water pump started leaking during winter of 2021/2022, but because was laid off due to covid I couldn't fix it. I had heat, barely, so just drove the truck only when needed. I finally was able to replace the water pump in Jan 2023. Did myself, had no known issues, to me anyways, when I replaced it. About two weeks after replacing the water pump, the heater core went, so late Jan 2023, was the first time. Took it to the garage as it was too big of project that I wanted to do. They replaced with after market. Later Feb 2023, it failed and they replaced with different after market. April 2023, it failed again, they replaced with a dodge heater core. And now July 2023, THAT dodge heater core has just failed. They are at a loss as to why or how it could fail so many times. Obviously they are getting tired of doing this work for free, and I'm getting tired of taking it to them.

Any theories or suggestions on what we are missing that could result in four heater cores failing in short order? The heater core is not rocket science, but good grief something is "chewing them up".

Thank you!

 

[mtnrider]

Define "fail"? What exactly was the issue.

.

 

[Burla]

Bad fuse or ground, do you have high water pressure? Maybe the new water pump? All the fails are after the water pump install, check water psi.

 

[bradlogan]

That’s interesting, had not realized that one. Thanks!

 

[Jeepwalker]

Has any one cut one of these heater core's apart to see what's going on inside? Are they leaking at the braze joints (or where?)? What's your water treatment look like?

Some possibilities could include:
1) pH totally out of whack. High ph eats aluminum. Guess what the thinnest aluminum part is? It doesn't mean it will eat a hole, all that's necessary is eating around a braze joint. Are they reusing your old coolant every time? Ask them to do a pH test. That should solve this question. Remember, coolant contains components to help reduce corrosivity, even if the pH measured is slightly outside of the 'safe' range. pH strips are terrible in accuracy, which is what most shops use. A good digital meter is much better...but must be properly calibrated or checked against a known set of pH buffers, of different known pH levels. Then you know your meter is reading properly. See charts below.
2) Bad engine ground and somehow the heater core has become the anode?
3) Too much pressure (Per Burla above). But to add ....it high pressure can be caused by a bad headgasket too. A headgasket can be 'semi-bad' for quite a while prior to a full-on white-out! LOL. How does the upper radiator hose feel when the truck is warm? Do you hear gurgling in the AM when you go to drive the truck? Do you smell combustion through the radiator? Bubbles in the coolant at higher rpm's.
4) 4 bad heater cores in a row. Unlikely, but certainly a possibility. Maybe there was a bad run of H/C's where braze joints are weak. Or the way they are packaged, they take too much abuse via shipping which weakens the inlet pipe braze joint.
5) Incompetent dealer tech getting 'rough' with the h/c during install.


These two charts say a lot: Aluminum is low nobility ...meaning it pretty freely gives up it's electrons compared to many metals (like Copper). And 2) Too high of a pH is good for iron, but not for Aluminum. Meaning a high pH will cause AL corrosion. In a mixed Iron/Aluminum system, a pH of aroud (or just under) 9.0 is within the narrow window for both metals. Copper core heater cores (like back in the old days), copper doesn't readily give up it's electrons (as easily). It could withstand coolant neglect a lot more.

 

[Jeepwalker]

I checked my Dodge Ram's coolant pH yesterday and it measured 8.0. That's down from where it was last fall. It' a safe environment the aluminum heater core and components, but I need to bump it up closer to 8.8 to satisfy the iron components (engine ..lol).

Ironically my other vehicles pH haven't changed.

 

[bradlogan]

Define "fail"? What exactly was the issue.

.

Coolant hose attached to it ends up releasing coolant all over passenger floor

 

[bradlogan]

Bad fuse or ground, do you have high water pressure? Maybe the new water pump? All the fails are after the water pump install, check water psi.

As for the fuse, can you explain? I didn’t think the core had a fuse (and how would that result in coolant pouring out?).

 

[Jeepwalker]

So, is it the Hose? Or a H/C braze joint on a fitting near the hose?

 

[Burla]

As for the fuse, can you explain? I didn’t think the core had a fuse (and how would that result in coolant pouring out?).

One would have to mention coolant was flowing out to rule that out, now that it is mentioned, it wouldnt be that.

 

[Wild one]

Coolant hose attached to it ends up releasing coolant all over passenger floor

Are the hoses the original molded hoses,and are they properly routed and attached to the holders on the side of the engine

 

[bradlogan]

So, is it the Hose? Or a H/C braze joint on a fitting near the hose?

I don’t know. The mechanic has done all the replacement. But something I can ask him tomorrow. There is no warning before I start leaking coolant. Engine temp is 100% normal, and then all of sudden it leaks out fluid.

 

[GTyankee]

Did the mechanic ever take out the whole dash board & remove the heater or condenser ?

OR

is the leak where the 2 heater hoses that go from the water Pump to the firewall. Is the leak right at the firewall & the water is spraying inside of the cab ?

to give you an idea of what you would have to do, IF the heater core is leaking.
Forget that the truck in this video is an Diesel, inside the Cab, all 4th Gen Rams are the same

Replacing the Heater Core on a 2014 RAM 2500

In this video I walk you through how to replace the heater core as well as how the ac/heating system works in a car

www.youtube.com

Another thing, IF you remove the Heater Core from the Ram, have someone check the 4 Doors inside of the HVAC box
There are several videos on how to do it properly

 

[bradlogan]

Are the hoses the original molded hoses,and are they properly routed and attached to the holders on the side of the engine

the hoses are orig. they go from the water pump to the engine wall, then separate hoses inside the cab go from inside engine wall to heater core. the last core installed was apparently dodge brand, and I assume all cores have the moulded hoses from the core to the engine wall. Since it was licensed garage, I'd assume that the were prop. routed. But as the saying goes, "when you assume, you make an ass of you and me".

 

[zrock]

im still not seeing why the core was replaced when the inlet/outlet hose is leaking and coming off? To me that would be a bad hose and if they are a plastic lock on the end i would bet they broke the hose on the first install so its not locking all the way. Need a better explanation as to why the connection is leaking.

 

[bradlogan]

Did the mechanic ever take out the whole dash board & remove the heater or condenser ?

OR

is the leak where the 2 heater hoses that go from the water Pump to the firewall. Is the leak right at the firewall & the water is spraying inside of the cab ?

to give you an idea of what you would have to do, IF the heater core is leaking.
Forget that the truck in this video is an Diesel, inside the Cab, all 4th Gen Rams are the same

Replacing the Heater Core on a 2014 RAM 2500

In this video I walk you through how to replace the heater core as well as how the ac/heating system works in a car

www.youtube.com

Another thing, IF you remove the Heater Core from the Ram, have someone check the 4 Doors inside of the HVAC box
There are several videos on how to do it properly

yeah, the whole dash board is removed, I know that (had some issues on wiring not fully connected the first time). I do not know exact spot of leak. I know that on the last two fails, lift the passenger floor mat, and the underlying carpet is soaked. Earlier fails, I had coolant spraying in the cab, but that was because I didn't catch it in time. There is no coolant leakage in the engine where the moulded hoses and the rubber hoses are clamped together. SO since there is no leakage in the engine bay, I assume it has to come from the heater core itself or the moulded hoses at the heater core. Assuming only it is one of those two spots, again, what out of my rad or water pump, could make multiple core's fail? I've got no leaks out of the rad. I replaced my water pump in Jan 2023, I did that work myself. it went 98% fine, the ONLY issue on the water pump reinstall was that out of 16 bolts that went back in, ONE bolt did not go in correctly, and I need to replace. But I've talked to other mechanics and they say that ONE bolt would not cause any issues.

 

[bradlogan]

im still not seeing why the core was replaced when the inlet/outlet hose is leaking and coming off? To me that would be a bad hose and if they are a plastic lock on the end i would bet they broke the hose on the first install so its not locking all the way. Need a better explanation as to why the connection is leaking.

Since there is no leakage in the engine bay, where the moulded hoses connect to the rubber hose, it is my guess that the leak is coming from core itself OR the moulded hoses that connect the core. I have not physically seen any of the damaged core's (yeah bad me), so I just though the moulded hoses were permanently attached to the core. so one as to replace core and moulded hoses together.

 

[bradlogan]

So, is it the Hose? Or a H/C braze joint on a fitting near the hose?

there is no leakage in the engine bay, so it is not the rubber hose from the water pump, or at the engine wall where the moulded hose and the rubber connect. I'm going to see if the mechanic remembers if leak was from the core itself or joints.

 

[Dean2]

There is no way 4 Cores went bad in that short a period of time, especially given they were all different makes and the last is OEM. Bad PH, etc doesn't eat a core in 30 days. I would check the pressure in the system as that being too high could be part of the issue. Even if the pump was putting out too much pressure the rad cap should vent it so I would test the cap. If the cap is not venting at the right pressure and holding too much pressure in the system that could be part of what is causing the leak. In all likelyhood however, your recurring leak is the hoses that attach to the core. Fix those and the core won't leak any more.

 

[bradlogan]

Has any one cut one of these heater core's apart to see what's going on inside? Are they leaking at the braze joints (or where?)? What's your water treatment look like?

Some possibilities could include:
1) pH totally out of whack. High ph eats aluminum. Guess what the thinnest aluminum part is? It doesn't mean it will eat a hole, all that's necessary is eating around a braze joint. Are they reusing your old coolant every time? Ask them to do a pH test. That should solve this question. Remember, coolant contains components to help reduce corrosivity, even if the pH measured is slightly outside of the 'safe' range. pH strips are terrible in accuracy, which is what most shops use. A good digital meter is much better...but must be properly calibrated or checked against a known set of pH buffers, of different known pH levels. Then you know your meter is reading properly. See charts below.
2) Bad engine ground and somehow the heater core has become the anode?
3) Too much pressure (Per Burla above). But to add ....it high pressure can be caused by a bad headgasket too. A headgasket can be 'semi-bad' for quite a while prior to a full-on white-out! LOL. How does the upper radiator hose feel when the truck is warm? Do you hear gurgling in the AM when you go to drive the truck? Do you smell combustion through the radiator? Bubbles in the coolant at higher rpm's.
4) 4 bad heater cores in a row. Unlikely, but certainly a possibility. Maybe there was a bad run of H/C's where braze joints are weak. Or the way they are packaged, they take too much abuse via shipping which weakens the inlet pipe braze joint.
5) Incompetent dealer tech getting 'rough' with the h/c during install.


These two charts say a lot: Aluminum is low nobility ...meaning it pretty freely gives up it's electrons compared to many metals (like Copper). And 2) Too high of a pH is good for iron, but not for Aluminum. Meaning a high pH will cause AL corrosion. In a mixed Iron/Aluminum system, a pH of aroud (or just under) 9.0 is within the narrow window for both metals. Copper core heater cores (like back in the old days), copper doesn't readily give up it's electrons (as easily). It could withstand coolant neglect a lot more.

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Fascinating info! Since all h/c were of different manufactures, weak joints is highly unlikely. reusing coolant, LOL! except for this time, most of it leaked out. I believe, though not certain, that whatever coolant was in rad, was just added to, vs flushed. I have no signs of a head gasket issues. Oil was just changed - just black. No coolant loss, no over heating, no smoke, no gurgling. I think idle is fine, i have a cracked exhaust manifold so the sound from that is somewhat distracting. But generally once the engine is warmed up, my idle is just fine. besides, on the pressure front, wouldn't the rad gasket blow if my pressure was to high? I will check the PH and confirm the pressure.