Heater Not Blowing Hot

[68PowerWagon]

are both heater core hoses hot ? if the heater has worked fine in years past then i would suspect the blend door. blockage of the core seems highly unlikely imo

Checked yesterday, both heater core hoses are hot. This one has me baffled!

 

[68PowerWagon]

This thing is really ******* me off! Left for work this morning, barely warm coming out of the heater. Coming home from work so hot I could barely keep my hand on the vent. Grant it ambient temp this morning was about 35 & tonight was about 45, but that shouldn't make that much difference.

 

[crazy jerry]

did you verify the blend door is working ? sounds like everything else is working fine

 

[68PowerWagon]

did you verify the blend door is working ? sounds like everything else is working fine

Yes... I can hear it moving & can feel the temp change when I move my temperature controls.

 

[Ribtipram]

Maybe a strange question but on the days its blowing hot do you notice a difference in sound. Like the way the air is blowing on high

 

[68PowerWagon]

Maybe a strange question but on the days its blowing hot do you notice a difference in sound. Like the way the air is blowing on high

Nope

 

[crazy jerry]

ive seen cores get partially clogged but that was on 20yo vehicles. is the engine temp doing anything weird ? that would certainly throw check engine lights though. i still think its something under the dash or heater controls

 

[68PowerWagon]

A guy that responded to a post in the interior section stated that he has had to replace the heater core on his 2014 twice so far. He opened up the first one & said it was plugged up with casting sand. I guess I should try doing a flush! I normally don't anything like that until around 100k.

 

[BW2014]

A guy that responded to a post in the interior section stated that he has had to replace the heater core on his 2014 twice so far. He opened up the first one & said it was plugged up with casting sand. I guess I should try doing a flush! I normally don't anything like that until around 100k.

My 2014 6.4 has had this issue as well, very little heat when below 30 F. I'm trying to research if the HD's with 6.4's use the 3 way coolant valve as I've read the 1500's use, and if it may not be flowing coolant to the heater core.

 

[RW03]

Was there ever a resolution to this issue? I'm having the same problem.

 

[68PowerWagon]

I currently am just putting up with mine. I don't want to take on the job of removing the heater core & I sure don't want to have to pay for it to be done. Most likely your blend door is hung up or your core is plugged up.

 

[bigrob713]

I just went thru this on my new to me 2014 6.4 2500. Mine does not have a 3 way coolant valve. Replacing the heater core fixed the problem. I had flushed it prior and replaced the thermostat thinking it was stuck open. It took a long time to get above 185* before I replaced the thermostat. These two things did nothing to increase heat output.

 

[crazy jerry]

I currently am just putting up with mine. I don't want to take on the job of removing the heater core & I sure don't want to have to pay for it to be done. Most likely your blend door is hung up or your core is plugged up.

have you tried to diagnose it at all? hose should be ~170. if the core is stuffed up its seems like the output side would be a fair bit colder. maybe blend door isnt swinging in the full range. casting sand seems like a rare far fetched scenario but maybe it could happen. from the hose locations it appears the core is behind the glovebox somewhere. couldnt be a terribly difficult job if thats what it boils down to

 

[bigrob713]

have you tried to diagnose it at all? hose should be ~170. if the core is stuffed up its seems like the output side would be a fair bit colder. maybe blend door isnt swinging in the full range. casting sand seems like a rare far fetched scenario but maybe it could happen. from the hose locations it appears the core is behind the glovebox somewhere. couldnt be a terribly difficult job if thats what it boils down to

It's not crazy difficult, but it is involved. Drop the steering column, lift dash up and back, reclaim refrigerant , disconnect evaporator, disconnect hoses and remove entire air box. The heater core is of course inside the airbox. These directions are very streamlined obviously. Takes 5-6 hours.

 

[crazy jerry]

It's not crazy difficult, but it is involved. Drop the steering column, lift dash up and back, reclaim refrigerant , disconnect evaporator, disconnect hoses and remove entire air box. The heater core is of course inside the airbox. These directions are very streamlined obviously. Takes 5-6 hours.

i have the factory service manual but never looked at the heating section. after browsing it tonight i see what you meen. hvac housing has to be removed since the core sits in front of it

giving it some thought heres what im going to do if i was in his shoes

like i said before .check the firewall core hoses with thermal gun. mine were 170 inlet. 160-170 outlet depending where i measured. this gives strong indication theres no core blockage so ill move on to the blenddoor motor and dash temp knob. manual shows motor just behind the glovebox door and mentions plugging in a scanner to check for faults of the motor or temp knob

going back to the firewall hoses. if the outlet temp is moderate to significantly lower than inlet, say only 120*, its reasonable to assume the core may have blockage. however, i see no way a newish core would have corrosion buildup on the tube wall but rather just loose sediment accumulation. im unplugging the firewall hoses, going to oriellies for two 3' pieces of hose and hooking them to the core nipples. put one toward the ground into a bucket and hook a garden hose to the other. turn on full blast. swap garden hose to the other sise and repeat. this will get any sediment out

 

[MSgtZ]

So I took mine to the dealer as my temp gun has died for good and my hands can only feel warm or cold, and not with a great degree of accuracy either. Problem is a plugged heater core. I don't have the time with work at the moment to tear it apart so they are doing that and a couple of other maintenance items that need to be done. The darn labor charge for 9+ hours for them to do is going to suck big time however.

 

[bigrob713]

So I took mine to the dealer as my temp gun has died for good and my hands can only feel warm or cold, and not with a great degree of accuracy either. Problem is a plugged heater core. I don't have the time with work at the moment to tear it apart so they are doing that and a couple of other maintenance items that need to be done. The darn labor charge for 9+ hours for them to do is going to suck big time however.

I'm pretty sure the book says 6 hours. I'm not sure where the extra time is from.

 

[MSgtZ]

the service manager might have quoted me all labor together as I had a leak between the trans tail shaft and transfer case that needed repair too.

 

[6.4LMegaMan]

My truck was not getting up to temp. It would make high 180s and then drop down to 170s. To me I figured it was something with the thermostat. I bought one off advanced auto parts online with a 20% off coupon for around $70 shipped. Easy to swap out and now my temps are back up to 210 or so and the heater is working great again. Sounds like I got off easy. Note the part number has changed from AB to AC. Maybe they fixed something?

Sent from my SM-N975U using Tapatalk

 

[TMyers]

I know this is an old thread but it has been resurrected because so many Ram owners in the 2013's and up have no heat.

Here's my findings on where my troubles were:

In 2013, Ram switched to OAT coolant, some prior years up to 2012 used HOAT. There is such a difference in the two, they cause gelling in the system. If your truck calls for OAT, you'll have to order it or go to the dealership. Parts stores have nothing compatible.

So, if you have ever had your coolant system topped off or like me, I had a water pump recall and the dealership replaced what was lost with HOAT, you have gelled slime in your heater core.

Here's what I did:

I disconnected my heater core lines under the hood. One at the firewall and the other at the intake. It's the squeeze type clamps. I purchased some fittings and a small piece of heater hose. I did nothing fancy, I just used electrical tape to tape and seal a fitting to my water hose and air compressor hose nozzles. Then I started blasting the core with the water hose in both directions. Full pressure, several times. After a while, I started using air blasts in both directions. I filled the core with water then blasted it out with air in both directions. On the last air blast, I refilled the core with a jug of distilled water. I put my truck back together and have had great heat ever since.