Possible heater Core issues

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LOFSFIRE

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2011 RAM Sport 5.7L

Yes, I'm having issues with warm air on the passenger side and cool air on the driver side. It was a hell of a day yesterday had an ejector pump that decided not to kick on and had dirty water luckily just on the basement concrete floor but was still a mess to clean up...

Onto the truck issue...
Instead of draining the coolant system myself I took it to one of the local shops and had them pressurized the system and clean everything out and flush it. It was a hundred bucks and took 15 minutes. Was hoping that would fix the problem... Also figured with everything else I going on yesterday, that was the quick check and hopefully fix. It is a little warmer on the passenger side than before the flush but basically the same driver side is still very cool... There is not now or ever been any coolant leaking inside the cab. The coolant has also been changed at 50,000 mi and then at 110,000 mi and then now at 140,000 mi.

The two hoses running from the heater core up to the water pump are running with pressure and are both are hot to the touch. Coolant temp at the time I checked was only 175.

Figured I'd take apart some of the dash and make sure the blend doors are working correctly as well.

My guess would have been heater core but with both lines from the heater core being warm that tells me fluid is flowing properly and since there's no leaks inside or on the ground I don't think it's a heater core...

But the blend doors all seem to to work. I then decided to flush it with CLR.

I found a post on a web forum and the guy explained the heater core design does not necessarily have to allow coolant to flow through the entire heater core. It's not a one-way street with an in and out the in and out basically floods the whole heater core... Short technically pass hot cooling from the sending one to the return line and appear to be functioning correctly... Does anybody know if this is correct?


So I did end up flushing the heater core with CLR and let it sit for 45 minutes. Then flushed 5 gallons of water through it as well, then ran vinegar through it and let it sit. Flushed another 10 gallons of water... Every time everything came out as clean as could be. I don't think there was one speck in any of it of dirt or grim. I also blew everything out with the air hose... Not one of those air guns meant for it just a air blaster nozzle with my hand holding the top of the hose and putting the nozzle up to it to kind of seal it off.

I refilled and then tested the heat which is a little bit better on the driver side but it's still really cool. Passenger side as much warmer. It's definitely an improvement from where I started at the very beginning but it's still not working correctly... I just can't believe if nothing came out and everything seems to be functioning correctly that there's anything wrong with the heater core but I don't know

With the day I had yesterday I realized I did not take the time to switch the hoses around and flow water in the opposite direction for the same process... Not sure if that helps loosen the gunk of it more or not but that seems to be order everybody's saying to do online...

Any other ideas on what this might be?
Is it worth taking it apart again to do the CLR flush again in the opposite direction. Does that really do anything?

What else it could be at this point...

Obviously I'm really trying to avoid doing the entire heater core especially if it's not necessary... But it kind of seems like everything's pointing that direction at this point...
 

tron67j

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There are a few threads out there that might help. One is:

 

Burla

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You put in some good work, maybe time to replace it? rmi-25 is what you should use for cooling systems, it takes anything in lines as in anything from rust to sticky coolant and encapsulates it and deposits it into overflow tank, I speak from experience on this one. But since you checked blend doors kudos no small job and with all you have done, might be time to get another heater core.

I might have missed it but was the coolant color good when you did all of this? clear?
 

Burla

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mr Google says you have gotten plenty of lifespan on that unit, for whatever this is worth... You didn't mention location, I'm sure heaters in cold places are more towards lower end then higher.

A car's heater core typically lasts between 8 and 15 years. However, there are several factors that can contribute to a heater core failing, including: age, corrosion, coolant issues, a faulty thermostat, and a clogged radiator.
 
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LOFSFIRE

LOFSFIRE

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There are a few threads out there that might help. One is:

Thank you very much, But I did search the form first and the web before posting. I actually found that same post... Guess I was hoping somebody else might have some insight as to something I missed or forgot to check.

You put in some good work, maybe time to replace it? rmi-25 is what you should use for cooling systems, it takes anything in lines as in anything from rust to sticky coolant and encapsulates it and deposits it into overflow tank, I speak from experience on this one. But since you checked blend doors kudos no small job and with all you have done, might be time to get another heater core.

I might have missed it but was the coolant color good when you did all of this? clear?
I will have to check that RMI-25 out.
As far as coolant color I checked it maybe a month ago and everything looked good. So I doubt that something catastrophic happened between now and then but to be honest when I took it into the shop to have them do the initial flush I had not checked it yesterday. Also with it just being changed out at 110,000 mi and only at 140,000 now there should not have been anything wrong with the coolant...
mr Google says you have gotten plenty of lifespan on that unit, for whatever this is worth... You didn't mention location, I'm sure heaters in cold places are more towards lower end then higher.

A car's heater core typically lasts between 8 and 15 years. However, there are several factors that can contribute to a heater core failing, including: age, corrosion, coolant issues, a faulty thermostat, and a clogged radiator.
I'm near Chicago, but in Indiana. So the southern tip of Lake Michigan. The truck was used but the guy kept excellent records on it and it was from Detroit. He was actually part of the team that designed the doors for the RAMs. One part that I know he had a hand in was the handle. Which I gave him a bit of a hard time on because I have a 2013 as well this 2011 is my son's. I've had mine since new. Right on the inside of the handle my paint is wearing off. I showed him on my truck and then we looked at the one I was buying. Sure enough it was the same way. It's just due to the way people grab the handle and open it, but he was shocked. Mine is copperhead pearl his was black so it's just easier to see because it turns black when the paints rubbed off.

I have the lifetime warranty on mine. He had a lifetime warranty on his as well however those are not transferable. So before purchasing it part of our deal was it would go to the shop I would pay any deductible plus the price we agreed on. I gave him a list of things that I wanted checked out and then he asked the dealer to check over other items. We tried to hit all the major components. The only real issue that the dealer was able to find was the emergency brake cable was rusted and did not work. They had the special order a few parts and ultimately took longer than they promised so they did not charge a deductible and everything was fixed at no charge. It really worked out well for me and him.

He was also a really good guy to do a car deal with. We've even stayed in contact as we found out we had some similar interest.
 

Burla

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Thank you very much, But I did search the form first and the web before posting. I actually found that same post... Guess I was hoping somebody else might have some insight as to something I missed or forgot to check.


I will have to check that RMI-25 out.
As far as coolant color I checked it maybe a month ago and everything looked good. So I doubt that something catastrophic happened between now and then but to be honest when I took it into the shop to have them do the initial flush I had not checked it yesterday. Also with it just being changed out at 110,000 mi and only at 140,000 now there should not have been anything wrong with the coolant...

I'm near Chicago, but in Indiana. So the southern tip of Lake Michigan. The truck was used but the guy kept excellent records on it and it was from Detroit. He was actually part of the team that designed the doors for the RAMs. One part that I know he had a hand in was the handle. Which I gave him a bit of a hard time on because I have a 2013 as well this 2011 is my son's. I've had mine since new. Right on the inside of the handle my paint is wearing off. I showed him on my truck and then we looked at the one I was buying. Sure enough it was the same way. It's just due to the way people grab the handle and open it, but he was shocked. Mine is copperhead pearl his was black so it's just easier to see because it turns black when the paints rubbed off.

I have the lifetime warranty on mine. He had a lifetime warranty on his as well however those are not transferable. So before purchasing it part of our deal was it would go to the shop I would pay any deductible plus the price we agreed on. I gave him a list of things that I wanted checked out and then he asked the dealer to check over other items. We tried to hit all the major components. The only real issue that the dealer was able to find was the emergency brake cable was rusted and did not work. They had the special order a few parts and ultimately took longer than they promised so they did not charge a deductible and everything was fixed at no charge. It really worked out well for me and him.

He was also a really good guy to do a car deal with. We've even stayed in contact as we found out we had some similar interest.
I looked up the heater core, I had no idea on our application, man this is a serious job, probably more commitment then a cam/lifter job. Might be worth a try, I like the 16 ounce size as this doesn't age well once open, so if you get this set leave other one closed until you opt to use it/. Call local radiator shops, this is the type of retailer that sells this stuff.

that guy sells maxodyne, maybe they bought rmi-25 or a subsidiary who knows.
 
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LOFSFIRE

LOFSFIRE

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I looked up the heater core, I had no idea on our application, man this is a serious job, probably more commitment then a cam/lifter job. Might be worth a try, I like the 16 ounce size as this doesn't age well once open, so if you get this set leave other one closed until you opt to use it/. Call local radiator shops, this is the type of retailer that sells this stuff.

that guy sells maxodyne, maybe they bought rmi-25 or a subsidiary who knows.
Yep, that's exactly why I was putting it off hoping for an alternative... I love the YouTube videos, one was "Change your heater core in 15 minutes!" I watched it thinking I was going to find some cool access point that it just fits through.... Nope, the video was 16 minutes long skipped all the duplicate steps, doubled speed on parts, and said reassembly was the opposite of how it came apart... Gee, thanks!

If it were not so cold this week I would just bypass the heater core and fill that up with the cleaner and let it sit for a week or so... But the kid needs heat...

He is with my ex every other day otherwise I would just let him park in the garage. At least the car would not be cold in the morning...

Luckily, I have the shop space to do the job, what I don't have is the time...
 

Burla

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yeah that is the one I saw crazy, capture freon, take out steering column, lol nuts.

I think most 12 volt heaters will blow fuse I dunno, maybe some type of battery heater can be helpful? It bothers me when I see what ram has done compared to other vehicles I have owned. Simple light bulbs aren't so simple. Heater core in a old Ford is an hour job, two at most.

little buddy heater uses those 1 pound cans, that could be a real solution.
 

Wild one

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yeah that is the one I saw crazy, capture freon, take out steering column, lol nuts.

I think most 12 volt heaters will blow fuse I dunno, maybe some type of battery heater can be helpful? It bothers me when I see what ram has done compared to other vehicles I have owned. Simple light bulbs aren't so simple. Heater core in a old Ford is an hour job, two at most.

little buddy heater uses those 1 pound cans, that could be a real solution.
How old a Ferd are we talking about,the dash basically has to come out to do the heater core on the 70's Fords. They're nasty trucks to replace a heater core on ;)
 

Burla

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How old a Ferd are we talking about,the dash basically has to come out to do the heater core on the 70's Fords. They're nasty trucks to replace a heater core on ;)
I had a 93,94,and 95 bronco. All of them you could pull the core out the glove compartment, lol? Actually under dash but you can also use glove box for access. So easy a kid could do it, just a couple wires to deal with. Not sure but I'm guessing f150's during that period the same.
 

Wild one

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I had a 93,94,and 95 bronco. All of them you could pull the core out the glove compartment, lol? Actually under dash but you can also use glove box for access. So easy a kid could do it, just a couple wires to deal with. Not sure but I'm guessing f150's during that period the same.
Those ones were almost as easy as doing the core on a 80's GM car,but the earlier body style Fords in the 70's were ugly to change the core on,they were no differant then a late model Ram,the dash had to basically come out so you could remove the heater box to get access to the heater core
 

GTyankee

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I have to ask, is your HVAC Single or Dual Zone

DUEL ZONE HVAC, looks like this & has the word SYNC on the control unit

1736242199223.png

single zone

1736242371667.png

my 2009 Dodge Ram 1500 SLT had the DUAL ZONE HVAC

I liked it because, i could control the amount of heat or cooler temps on either or just one side, or both sides
I could also send heated or cooled air to the rear seating area, the vent was at the rear of the floor console, or in some cases the front center seat
 
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GTyankee

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watch this


unfortunately, he did not show all of the gears inside of the old actuator, it looks quite similar to a watch inside of it.

He should have also showed how to tell if a Blend Door was still functioning inside of the HVAC box
-------------------------------------------------------

This is NOT a Ram
BUT it is the same basic way a Ram HVAC system works
& it shows how to tell if a Door is still connected to the keyed bushing that connects to the Actuator

 
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LOFSFIRE

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It has the DUAL ZONE HVAC

Also, that was the first actuator I checked and the door in side is definitely functioning. I could move it by hand you could hear and feel the open and close of it. In this truck his fan is very loud. I actually thought is had a leaf in the blower so I took that apart but found nothing so I'm assuming it a bearing or just that particular motor/ fan. My truck is very quiet... So when I was checking the actuators I unplugged the fan so you could hear each blend door open and close by changing the functions.

Also, now that I think about it the actuator does work but I only noticed it moving on initial start up. (Or at least remember seeing/hearing it move a the function change.) I did not check the heat when opening the door manually. I only verified that the actuator worked... Wonder if the actuator is going bad where it could work with no load but when installed it does not actual move... I guess I will double check that tonight. Boy I hope this is it....

I have to ask, is your HVAC Single or Dual Zone

DUAL ZONE HVAC, looks like this & has the word SYNC on the control unit

View attachment 558069

single zone

View attachment 558070

my 2009 Dodge Ram 1500 SLT had the DUAL ZONE HVAC

I liked it because, i could control the amount of heat or cooler temps on either or just one side, or both sides
I could also send heated or cooled air to the rear seating area, the vent was at the rear of the floor console, or in some cases the front center seat
 

Tominator223

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Sounds like blend door or hvac issue. Not h core. My 04 still has original h-core at 21yrs & 400 thousand + miles. I did have a blend door issue before though.
 

garrett_brown

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I have a 2012 with dual blend. I'm having a similar issue but not exactly the same. I start it up and everything works fine. I go somewhere, turn it off then come back, let's say an hour later and now my driver side is cold. It doesn't always repro, which is what has stumped me. The weird thing is sometimes I can crank the heat to 80+ and it will become warm again. My initial thought was a bad blend door but from what I've seen here that doesn't sound like it would be the case? I don't know exactly how they work but I would assume they won't close/change unless the heat is switched so turning it off then on again shouldn't do anything with the blend door?

If it's not an easy fix I may just take it to Dodge. The one smart thing I did, and I've only ever done it for this vehicle is purchase the lifetime warranty. They fixed the transmission and had to replace the engine. Those two cost me $200 bucks so I'm thinking $100 to let them troubleshoot and fix the problem is probably the better solution.
 

Sherman Bird

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mr Google says you have gotten plenty of lifespan on that unit, for whatever this is worth... You didn't mention location, I'm sure heaters in cold places are more towards lower end then higher.

A car's heater core typically lasts between 8 and 15 years. However, there are several factors that can contribute to a heater core failing, including: age, corrosion, coolant issues, a faulty thermostat, and a clogged radiator.
My 1989 D-150 Was originally from Cowboy Dodge in Wyoming, where it does get butt-freezing cold. The truck was equipped with an auxiliary battery and an electronic switch over control. That, and the cute tiny mechanical radiator fan, added up to a heater that got HOT post haste! I wonder if Dodge made that heater bigger considering where it's original bill of lading was.

I did away with that cute little fan and the shroud, and installed an aluminum radiator, a 15 inch Hayden fan and an automatic controller for Houston's broiling heat. Even then, that heater outperformed every car I've had, except my current Lexus daily driver.
 

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