Heater Not Blowing Hot

[68PowerWagon]

I have posted this on the HD forum but wanted to throw a wide net to see if anyone else is having these issues with the 5.7. Noticed last winter that it wasn't blowing hot air. This year it is just a little bit warmer than the ambient temp. Adjust the temp on the heater & I can hear the blend door moving & can hear a little bit difference in the tone of the air blowing. This makes me think the door is opening properly. Really kind of acts like the heater core is partially blocked. This is a 2016 2500 with the 6.4 & only 50k miles. Could my core be blocked already? Another guy on here that responded to a post on the interior forum said his 2014 with 100+k was on his second heater core. Cut it open & said it was plugged with casting sand.

 

[Burla]

Feel the inlet hose to heater core, you should feel the flow. If it's clogged I imagine the flow will be non existent if not very slow. I wish all rad hoses were clear, would solve so many issues and answer so many questions.

 

[68PowerWagon]

Feel the inlet hose to heater core, you should feel the flow. If it's clogged I imagine the flow will be non existent if not very slow. I wish all rad hoses were clear, would solve so many issues and answer so many questions.

Now that's some cool hoses! Never seen any like that before. Come to think of it, someone asked me a couple weeks ago if both hoses were hot. When I checked they were. So would that take the heater core out of the equation?

 

[KarL45]

Is your temp gauge showing a minimum of 180 deg? Also, check your pressure cap vent valve to see it is free. If not will could create a vacuum in the system and close your upper hose. Also, would suggest using the full shielded thermostat on the older engines. Night and day better regulation of the temp summer or winter. Agree, cool hoses.

 

[68PowerWagon]

Is your temp gauge showing a minimum of 180 deg? Also, check your pressure cap vent valve to see it is free. If not will could create a vacuum in the system and close your upper hose. Also, would suggest using the full shielded thermostat on the older engines. Night and day better regulation of the temp summer or winter. Agree, cool hoses.

Yes, after warm up, the temps run around 200-210*. I have always done most of my repair work myself... REALLY don't want to take this thing in to someone to fix, but I am really striking out on figuring out what the issue is.

 

[ram1500rsm]

I had the same issue in my 13 Jeep Wrangler. The heater core thing gets plugged up with cast sand from the heads. FCA seems to know about it but looks the other way. Dealer wanted $1700 to fix a $70 part. On the Wranglers it seems to be a big deal to get to it because of the location of the mfacker, the whole front console has to be disassembled inside the Jeep and on the engine side there is a lot of junk that needs to be removed before disconnecting the other side.

Hopefully it’s something easier to fix in the RAMs.

 

[Tach_tech]

I had the same issue in my 13 Jeep Wrangler. The heater core thing gets plugged up with cast sand from the heads. FCA seems to know about it but looks the other way. Dealer wanted $1700 to fix a $70 part. On the Wranglers it seems to be a big deal to get to it because of the location of the mfacker, the whole front console has to be disassembled inside the Jeep and on the engine side there is a lot of junk that needs to be removed before disconnecting the other side.

Hopefully it’s something easier to fix in the RAMs.

The whole dash has to come out for the heater core. It’s not bad to do if you know what you’re doing. The A/C has to be evacuated as well.

 

[68PowerWagon]

The whole dash has to come out for the heater core. It’s not bad to do if you know what you’re doing. The A/C has to be evacuated as well.

Man you guys are KILLING me! I seen a few youtube videos of people getting into the heater core & blend doors. Looks to be a HUGE task! Yesterday I directed half of the air to come out the upper vents & half to the floor vents. By doing this I was able to feel a difference in temp from the driver to passenger side. Driver side basically feels like it is re-circulating the air in the cab, passenger side was warm but not hot. This is with both temp settings on the highest level. Since flushing is not that involved, I think I will start with that first & pray that will fix it. Only 23* when I left the house this morning, so I am extremely thankful I have heated seats & steering wheel!

 

[Ribtipram]

Have you tried disconnecting the heater core and blowing it out to see if its clogged.

 

[68PowerWagon]

Have you tried disconnecting the heater core and blowing it out to see if its clogged.

No not yet. Where is it even at on these things? Do I have to rip out the whole dash to get to it? It doesn't get used in a really dirty environment so I wouldn't think that is what it is. I am hoping to really dig into it over the weekend.

 

[Tach_tech]

No not yet. Where is it even at on these things? Do I have to rip out the whole dash to get to it? It doesn't get used in a really dirty environment so I wouldn't think that is what it is. I am hoping to really dig into it over the weekend.

There is 2 hoses going to the firewall on the passenger side. Those are for the heater core. You can try backflushing it with a cooling system cleaner/hot water and compressed air if you have access to it. It might help it might not.

 

[jws123]

Blow the heater core out with water both ways re connect and burp it and you may get lucky if not . People always say its a hard job to replace the heater core and it is a pain in the ass but not really to bad. i did mine in 6 hrs there is tons of short cuts like keeping steering column in and only dropping it down ect. Mine was clogged solid on bottom or top forget what one but only had good heat on pass side.

 

[Ribtipram]

Got to be hoses going threw the firewall somewhere. Ill take a look when i get home.

 

[bassheadhemi]

can't it be the blend door?

Sent from my SM-N950W using Tapatalk

 

[Stevieboy96]

I am wondering if maybe a blend door actuator isn't fully engaging the blend door. I have had to order a couple on some older vehicle this last week.

 

[68PowerWagon]

Have you tried disconnecting the heater core and blowing it out to see if its clogged.

No not yet. Where is it even at on these things? Do I have to rip out the whole dash to get to it? It doesn't get used in a really dirty environment so I wouldn't think that is what it is. I am hoping to really dig into it over the weekend.

There is 2 hoses going to the firewall on the passenger side. Those are for the heater core. You can try backflushing it with a cooling system cleaner/hot water and compressed air if you have access to it. It might help it might not.

Going to try this first, & pray I don't have to rip the dash apart!

 

[jws123]

No not yet. Where is it even at on these things? Do I have to rip out the whole dash to get to it? It doesn't get used in a really dirty environment so I wouldn't think that is what it is. I am hoping to really dig into it over the weekend.


Going to try this first, & pray I don't have to rip the dash apart!

You dont do anything in the dash to flush/blow it out its just the 2 hoses . Also they dont get clogged on the outside they get clogged up on the inside un hook the 2 hoses flush it out multiple times both ways with the hose.

 

[68PowerWagon]

You dont do anything in the dash to flush/blow it out its just the 2 hoses . Also they dont get clogged on the outside they get clogged up on the inside un hook the 2 hoses flush it out multiple times both ways with the hose.

Yes I understand the first part. And yes some do get clogged on the outside. I have seen guys that have had to take condenser cleaner to them to get all of the gunk out. I plan on unhooking the hoses & flushing like you have mentioned. Next I am going to try throwing a bottle of Prestone Flush down in it & letting it soak for a bit. After that I plan on flushing the whole coolant system. It is just really weird that I am already having to do this! I have never done this to a vehicle that didn't already have over a 100k on it.

 

[Ribtipram]

Yes I understand the first part. And yes some do get clogged on the outside. I have seen guys that have had to take condenser cleaner to them to get all of the gunk out. I plan on unhooking the hoses & flushing like you have mentioned. Next I am going to try throwing a bottle of Prestone Flush down in it & letting it soak for a bit. After that I plan on flushing the whole coolant system. It is just really weird that I am already having to do this! I have never done this to a vehicle that didn't already have over a 100k on it.

Man lets hope just flushing threw the hoses works. Taking out the dash and everything sucks. Not that hard but just a ****** long job. Let us know what happens when you flush.

 

[Tach_tech]

Yes I understand the first part. And yes some do get clogged on the outside. I have seen guys that have had to take condenser cleaner to them to get all of the gunk out. I plan on unhooking the hoses & flushing like you have mentioned. Next I am going to try throwing a bottle of Prestone Flush down in it & letting it soak for a bit. After that I plan on flushing the whole coolant system. It is just really weird that I am already having to do this! I have never done this to a vehicle that didn't already have over a 100k on it.

If the outside of the evaporator/heater core is clogged with junk, you’ll have poor air flow.