2001 Ram 2500 4x4. 275,000 miles

My heater refuses to really get warm. From what I have read here that seems to be a common problem. I bought the "heater treater" and installed it on door actuator. Actually it was not broken but I put the metal insert in anyway. Before I reinstalled it I opened and closed the door manually to test it. The door moves easily. The core box is very hot but on very cold days I am only getting cool air. The mix works fine. Just replaced the coolant, no smell from the core although I can hear a small amount of water sloshing in the box. Just don't get it. Any ideas appreciated.

 

Please give some more specifics on "really cold" and how long the truck is running when it isn't getting really warm.

 

If you replaced the coolant I am thinking you did back flush the heater core, if you "can hear a small amount of water sloshing in the box' then the condensate drain is plugged and the heater plenum is filling with water, try clearing the drain first. If the drain under the hood in the firewall on the passenger side is clear then it's air in the heater core and you need to bleed it out.

 

Can you tell me how to bleed it.

 

Jstone

16 degrees. And the even after driving 35 miles to work it's still cold.

 

First..You need a winter front, at 16 deg F the condensation in the heater plenum will be frozen into a solid block of ice if it's not draining. To check the fluid level, when the engine is cold take the rad cap off and top it up if it's not full. If it is full park the truck facing up hill as the heater core is higher than the engine and this makes the rad cap the highest point. with the engine cold take the rad cap off and start the engine if possible have someone increase the rpm slightly, continue topping off the rad until just before the thermostat opens, do not let the rpm drop, at this point replace the rad cap and top off the overflow bottle.

 

There is a hose going to the heater core and a hose coming out. Where they're located at the firewall, feel them both when the engine is at full operating temp and if they're not the same temp then the core is blocked. If the core is hot and you're not getting hot air out of the heater then the only thing left is the blend door.

 

LOL, I have cardboard between the intercooler and the rad. with no larger than a 6" diameter hole for air to pass, and I have a hard time getting any decent heat at 16 degrees........ Without a good block, I wouldn't get ANY heat.

Before you freak out, try a good cardboard blocker, you are in Texas, so figure maybe an 8" diameter hole for air thru the center?

 

DO NOT put cardboard between the radiator and the intercooler..... Too many people experience problems when trying this. Not only can it cause the A/C compressor to fail if you run the defrost because it turns on the compressor.....and just so you know the compressor also runs on 5 out of the 7 HVA/C selections too.....but it can cause the engine fan blades to vibrate from turbulence and also cause the engine fan to run all the time if the hole isnt placed directly over the fan clutch thermostat. Plus it can easily cause unsuspected overheating in the radiator but yet cause the intercooler to get far too cold. And super cold intercooler temps are one main reason why the engine will run too cool since it drops the combustion temps too low. All around its just not a good idea. If you need some sort of winter front to help combat extreme cold weather and you dont want to spend the money for a correct winter front then go get some duct tape and cover the front of the grill holes or cut out some cardboard or plastic and ziptie them to the grill holes. That will at least allow normal air flow for the engine fan but lessen the cold directly hitting the radiator and intercooler.

In regards to weather temps and heater temps, if you aren't getting good heat out of the heater and you think its related to the ambient weather then you probably have a bad thermostat or the wrong thermostat. If the engine is maintaining its normal 190* (which it easily should in 16*F) then there's no reason you shouldn't be getting heat from the heater. Now if we're talking well below 0* in frigid arctic weather then you may have a reason to say the weather is just too cold.

 

Hmm, I had never heard that. I haven't been doing it but for a couple of years, don't have a specific aversion to buying a winter front, just lazy I guess.

Now I have to start looking for a winter front........

But she runs 190 all the time in the spring/summer/fall, it is only winter that I have a heck of a time keeping heat in the engine.

 

Didnt think you're lazy..... Its just that most people dont realize the potential problems which can happen from sticking cardboard between the radiator and intercooler.
And it sounds like you may have a "lazy" thermostat if the engine cant stay warm in the cold weather. In saying that, aftermarket marketing has people believing that cold air intakes and huge exhaust are always better but fail to inform people that diesels need some intake heat to achieve optimal combustion temps.