Heater Core Clogged Already?

[4xdad]

If it’s a chronic problem you could put a filter in line easily

 

[Sherman Bird]

Over the last several weeks I have noticed the air coming out of my heater is just barely warm. Turned the temp setting as high as it will go but I don't seem to be getting much heat. Surely don't have a clogged heater core already? Possibly something in the electronics is not telling it the temp I set it at?
Truck is a 2016 2500 6.4 with 40,000mi.

Start the truck and get it fully up to operating temperature.
Turn the heat up fully and raise the hood and feel the heat of the 2 heater hoses... carefully.
If there is a big difference in their temperature, i.e. one is cooler than the other, there id inadequate flow through the core.
If they are equally hot, the problem is in the HVAC air distribution inside the cab. There ya go!

 

[Sherman Bird]

It’s not the blend doors it’s the heater core plugs up. I have flushed my heater core out every three weeks through the cold season. I get heat for 2 1/2 three weeks and then it stops until you hit a really big bump sometimes that’ll jar some of the sand out. What I’d like to know is why First second why doesn’t ram warranty this crap and third is there someway to put a filter system on these trucks to stop that sand from going through the core

My solution for chronic heat loss on a 2002 Ram with the 4.7 was to remove the rear most "freeze" core plugs from the block, then douche the coolant passages of the block wit a garden hose and a high pressure nozzle.

After I did it, I was filthy; covered in crud from inside the block. The customer never had any more trouble.

 

[mtnrider]

Start the truck and get it fully up to operating temperature.
Turn the heat up fully and raise the hood and feel the heat of the 2 heater hoses... carefully.
If there is a big difference in their temperature, i.e. one is cooler than the other, there id inadequate flow through the core.
If they are equally hot, the problem is in the HVAC air distribution inside the cab. There ya go!

Unfortunately, it's not that simple, enough water bypass's the coils of the core (when they are clogged) to give you equal heat on both hoses but no heat in the cab.

The issue is a clogged heater core, it always is on the 4th/5th gen trucks. The 3rd gens had blend door issues but it's almost unheard of in the 4th gen+.

.

 

[4xdad]

I reverse flushed it first and changed the flow back and forth a couple of times. It seems to have worked for me

 

[4xdad]

For me I noticed my truck was not heating up properly and not blowing warm air when it was-30c. I think that the problem was the combination of both problems. I noticed that the temperature wasn’t right and it was taking to long to rebuild. Now that I have done the flush and thermostat it seems to work well but it isn’t -30 anymore

 

[Atcer2018]

I’ll add to the confusion. A few years ago my daughter had a boyfriend with a F150 that had little to no heat. We flushed the cooling system twice. Replaced the thermostat. Back flushed the heater core twice and still no heat. As a last attempt we pulled the water pump. The blades of the pump were deteriorated so badly it struggled to move water. New water pump solved the problem but that was a Ford and Rams are known for plugged heater cores.

 

[Lsujker]

My solution for chronic heat loss on a 2002 Ram with the 4.7 was to remove the rear most "freeze" core plugs from the block, then douche the coolant passages of the block wit a garden hose and a high pressure nozzle.

After I did it, I was filthy; covered in crud from inside the block. The customer never had any more trouble.

I have read about this method. Any issues with corrosion internally from using tap water? Can't get it all out. Guess on a 20 year old motor, who cares.

 

[Rock]

My 2018 started the no heat problem last winter. I watched a video of a guy flushing his heater core using a tool that you could hook water and air to at the same time. The idea was to run the water then pulse the air to break loose the sand, but not to much air at once, just pulses. Once done and everything hooked back up and engine at normal temp;
turn on heater full temp and high fan. If hoses are the same temp, then heater core is not taking any heat away from the water. If hoses are noticeably different then you should be good.

 

[Sherman Bird]

I have read about this method. Any issues with corrosion internally from using tap water? Can't get it all out. Guess on a 20 year old motor, who cares.

The truck wasn't anywhere near 20 years old at the time... it was 7. He had inadvertently mixed coolant types and turned the cooling system to a peanut butter consistency. We used Oxalic acid initially and broke it down so we could flush the system. As far as getting tap water out, I'm not one to split hairs. We flushed it, acid treated it, used copious amount of baking soda to neutralize the acid's chemical activity on metal surfaces, replaced the head gaskets and removed the freeze plugs, I did the pressure flush to the block, then we ran a garden hose through the running engine for nearly an hour.

After draining everything we could as well as we could, we mixed the orange coolant 50/50 with distilled water, and installed a new t-stat, the coolant and a new reservoir and cap. He was still driving the truck every day with no issues as late as 2015. Good 'nuff.