Dodge Ram Heater Core Problems 

Q#1 2019 Dodge Ram 2500, Is there a way to repair the heater core in a Dodge truck without having to replace it?

Last winter I noticed my heater wasn’t providing good heat.   I had the thermostat changed and I had the cooling system flushed, which didn’t seem to make much difference.  The garage told me the heater core could be restricted and will likely need to be replaced. They said they could try back flushing the heater core but wouldn’t guarantee that it would fix the problem.  When I got the estimate, it was a bit shocking.  The cost of the heater core wasn’t bad, but the labor was like 8 hours to change it.  I looked on the internet and it looks like you must take the dash completely out of the truck to change the heater core.  Is there a way to repair the heater core on a Dodge truck without having to replace it?

 

A#1

Replacing a heater core in your Dodge truck or many other vehicles today is labor intense!  The heater core in most cases is not that much money, but the time it takes to remove and replace it is a totally different story.  And yes, you do have to remove the dash along with lowering the steering wheel, disabling the Air Bag System and, once you remove the dash you can then remove the HVAC (aka heater box) to get to the heater core.  You need to drain the A/C system too!

 

 Heater Core Problems

Back in the day, if you didn’t flush your vehicle’s cooling system regularly, there was a good chance that your radiator or heater core would become clogged/restricted.  The blockage in a radiator was pretty easy to pick-up on because your vehicle would start running hot or even overheat.   Most times a back flush of the radiator or replacing the radiator core was the fix. 

Of course, with a heater core you wouldn’t notice it was a problem until the temperature dropped and you needed to get the ice off the windshield.  Heater cores back then were pretty much the same as radiators, with big tubes for the coolant to travel through; you could almost always backflush the heater core and restore it to normal operation.   The only time we would replace a heater core was if it was leaking, or it was plugged so bad that back flushing wouldn’t work.

 

Long Life is Not Long Life

So we see a couple of reoccurring problems with Dodge trucks and their heater cores.

But let's start with the Dodge Factory Service Manual saying that you only have to flush the cooling system every 10 years or 150,000 mile whichever comes first.  If you follow this recommendation, you’ll likely need a heater core replacement before a cooling system service.

Dodge’s long-life coolant is not long life and needs to be changed sooner.  We recommend every 60k miles or 5 years.  Not trying to oversell this service, but a coolant flush is much less money than a heater core! 

 

 We’ve seen the coolant in Dodge trucks start to discolor at 50k miles, a change in color is a sure sign of the coolant’s additive package breaking down  and problems are just around the corner if ignored.  The fact is most of the heater cores we replace are in vehicles with an age or mileage that is less than the recommended coolant service interval recommended by Dodge.

Human-made problems with Dodge cooling systems

1. Using tap water to reset the coolant level. Using tap water to top off or mix your own 50/50 blend is a big no no.  If you must, use distilled water only
 2. Adding the incorrect coolant; you can’t mix coolants in any of today’s vehicles, doing so is going to cost you in repairs.  Adding the old school green coolant which is an inorganic acid technology (IAT) with the new coolant is a recipe for heater core problems.  The old school green stuff is for older, and I mean older vehicles made before 2000. 

Mixing different types of coolant can cause chemical reactions that can damage your engine. For example, mixing green coolant with orange coolant can lead to a chemical reaction that creates a gel-like substance that can clog your radiator and engine passages.

If you must top off your cooling system in your 2019 Dodge you should use premixed 50/50 that is an Organic Acid Technology (OAT) type coolant.

 

The heater cores in today’s vehicles have much smaller passages inside them for the coolant to flow through and when the coolant goes bad causing corrosion, they will easily become restricted or plugged

 

Here is the problem we see the most  

Somebody mixed old school coolant with the new.  This results in a chemical reaction in the cooling system.  This reaction causes the formation of brown, gelatinous sludge in the reservoir, radiator and heater core that can completely block the cooling system over time.

This is what we see most often and when this happens it’s nearly impossible to remove the stuff.

 

The heater core shown in the image was restricted with that gelatinous sludge.  The stuff is crazy sticky and we have not found a way to dissolve or to flush it out of the cooling system.  The tip on that felt marker is very small which gives you a good idea of how small the passages are in today's heater cores.     

Conclusion

1. It is not a good idea to mix coolants. The mixture you use should be one that your car’s manufacturer suggests because it will keep your engine operating at its best and protect it from overheating damage.
2. Flush your cooling system more often than the manufacturer’s recommendation.  A cooling system flush is much more affordable than a heater core.  Not trying you upsell you here , just want to save you money

Other Fun Coolant Facts

Are There Different Types of Coolant?

Yes, there are mainly three types: Inorganic Acid Technology (IAT), Organic Acid Technology (OAT), and Hybrid Organic Acid Technology (HOAT). Each type has different chemical compositions and properties.  But it’s not simple in today’s automotive world.  Below is a list of commonly used coolants.   In the end, mixing coolant types is not in your best interest.  Read the label on the container and make sure it is compatible with your vehicle application.  Just to keep it challenging,  don't use the color of the coolant as a guide, some different color coolants are compatible. Once again, read the information on the antifreeze container to be sure it is correct for your vehicle.    

 

 

Antifreeze type	Color	Inhibitor technology
OAT (Organic Acid Technology)	Orange	Organic acids
HOAT (Hybrid OAT)	Yellow	Silicates and organic acids
HOAT (Hybrid OAT, Phosphate-free)	Turquoise	Nitrite, amine, phosphate, and silicate-free
P-HOAT (Phosphated HOAT)	Pink or blue	Phosphates and organic acids
IAT (Inorganic Additive Technology)	Green	Silicates
Si-OAT (Silicated HOAT)	Purple	Silicates and organic acids

 

Northwood Garage Saves You Money on Heater Core Replacement
AAA benefits, save 10% on repairs

As a AAA member you receive many discounts, one you may not know of is the 10% you can save on repairs at the Northwood Garage.  If your car or truck is towed in by AAA your discount happens automatically on the needed repairs and any additional repairs you have performed.

Benefits don’t stop there, when you come into the Northwood Garage show us your AAA membership card.  Current members will receive a 10% saving on brakes, timing belt and most any other service your car or light truck needs.

Serving Northwood & surrounding communities automotive needs since 1955