2nd Gen Non-Engine/Transmission Cold Truck

[DGamelin]

We can't seem to get enough heat in the cab. It won't defrost the door windows. I never thought the engine got warm enough, new thermostat and thermal switch. I just figured the gauge in the cab was off. It reads about 140, I haven't checked it with a hand held gauge yet. My question is, is there more than one clutch fan available? It has been cool here but I didn't think the truck ever ran hot enough.

2000 2500 2wd cc 354 auto
2004.5 3500 4wd cc dully 373 6-speed

 

[PC12Driver]

Driving or idling? Is the fan roaring like it's locked up?

 

[DGamelin]

The fan never roars. When it is shut off and you turn it buy hand the drag fells like a new one, it doesn't feel bad. We got the truck from taxes, it must have been replaced it just feels tight. I was wondering if there is a standard and a HD. I will check on monday to see if dodge had a regional part number for them. We delivered a tractor today the truck never worked hard today, we were driving in white out conditions.

 

[JR]

Which brand and degree stat did you use? They offer a 180 and a 190 degree, the 190 is what should be used for engine efficiency, and alot of the aftermarket brands tend to fail right out of the gate. OEM cost a little more, but are much more accurate.
If you live in a cold climate the 200 degree stats for the 6.7 are a drop in and will give your engine a little extra heat.
Winter fronts help alot also if you don't have one.

 

[DGamelin]

I bought it from dodge it is a cummins. I don't remember the degree but I am all most sure it was a 190. It was what stock replacement called for. I will dig up the invoice for it. When I took out the original one it looked good. I have the grille closed off.

 

[rkressg]

Cover the radiator with cardboard. In the winter, I keep it between 70-80% blocked, put the cardboard between the radiator and the intercooler.

It could also be a plugged heater core (assuming it is full of coolant). If the heater core is plugged, you can try flushing the system.

 

[BDaugherty]

When i replaced the thermostat on my 01 with a 190 stant, i had poor in cab heat afterwards. I later found air trapped in the cooling system that hadnt quite purged correctly. I added about a gallon of coolant once the air worked its way out. After that, the heater worked normally. Thats not to say it was awesome, but it was back to factory performance. I live in georgia where it doesnt get cold very often and do not have a winter front.

 

[MLee]

We are assuming that your coolant level is up. Some have removed there fan blade in the cooler months. Heats up a little quicker. If the truck is worked then you must pay attention to the temp gauge.

 

[mwilson]

Check both lines going to the heater core and see how far off the temp is between the two.

If you are referring to the 2nd Gen in your signature it sure sounds like the heater core is partilly plugged. I have to flush mine every couple of years or the in cab heat will drop off.

Also, I see that you are in the U.P.
What kind of ambient air temps are you operating in??

Mike.

 

[DGamelin]

Yes it is the 2nd gen, we haven't had it long and have been working the bugs out of it. It has been -10 to 7F for over a couple of weeks now. The run we were on yesterday the high was 0. But even when it is 20 or better the engine doesn't seem to be up to temp. I sure didn't want to pull the heater core. I am in the shop now and the clutch fan is the oem one at a 167k I wonder if it has a little more drag then it should have? It feels fine. I am going to install an electric vacuum switch so I can put the heater on recirculate when ever I want to help heat up the cab. Right now it only works on max ac not defrost. I zipped tied the door shut so it would recirculate on defrost and the cab heated up about 4 times faster. So the temp in the cab was ok but you had to scrape the door windows to use the mirrors. when we picked the truck in TX we had to add a can of freon to get the AC to work

 

[mwilson]

The windows will do that when on recirculate and defrost, that is why the heater controls and function do not allow that.

I have a post on here with my heater core flush using Home Depot chemicals. I'll try to find it for you.

Mike.

 

[mwilson]

Found it......

https://www.turbodieselregister.com...42847-Heater-core-flus&highlight=Heater+flush

Mike.

 

[DGamelin]

I don't agree that recirculate will make the windows frost up because the problem was there long before we tried it. As a matter of fact once we got some heat our windows got better. Some high end cars still have a recirculate button. We just got back from a ride into town to get freon and check water temps. The AC is not working. The heater core has just about the same temp going in as coming out so I don't believe it is restricted. The temp spread in and out was 3 to 6 degrees. I wonder if the heater core could be mated up with dust or something on the outside of the core. The hottest temp we saw going into it was 117. The water temp in the engine stayed in-between 120 and 140. The thermostat never opened. The radiator was at about 2 degrees, the upper hose was cold and the bottom hose was at best luke warm. The fan was cycling off and on and it shouldn't have done that but if the thermostat doesn't open what difference does that make. When looking at the radiator, the gap between the intercooler and the radiator, about 20% of the radiator in the shape of a big circle is clogged and not working anyways. I think most of this is the engine just isn't getting hot enough. I probably will change the clutch fan just to eliminate one more issue.

 

[JR]

In those cold temps you can just remove the fan and drive it without fear of overheating, providing your not working the engine hard. I would be inclined to try that first, the fans for the most part are a pretty reliable unit and not very failure prone. I've seen several in the 2nd gens go 300k+ miles. If it doesnt sound like a 747 all the time, its likely fine. For your engine to be that cold it would likely have to be locked all the time, and I dont know if even then it would keep your temps that cool.
The a/c compressor is used year around to remove mositure from your hvac system. If you don't have a/c, I would bet that is the culprit of the frosty windows inside. The recirc button idea is your call, but IMO find the problem, and that truck will roast you out once its warmed up. Even at 2 degrees this morning, I had my heat knob at the 12 oclock position going down the road and no frost issues inside at all.
As for the cool engine temps, you may try a manual gauge just to verify actual temps. With the radiator cap removed do you see good coolant flow when the stat opens? FYI all that grease your seeing is from the breather tube on the front of the engine. They can get so plugged up it will cause overheating problems in the summer. Probably not on your list of to do's at the moment, but your probably going to have to pull the radiator and degrease it at some point.

 

[NIsaacs]

You have a bad or cold thermostat, the engine should warm up when you drive it.

Nick

 

[mwilson]

One more reason to leave your heater on fresh air that some may not know.

Operating a vehicle with a modern heat and a/c system on fresh air creates a positive pressure in the passenger compartment. That makes a huge difference in cold air intrusion. If you are able to switch back and forth between fresh air and recirc on a very cold day give it a try. You will feel every sneaky little draft while in recirc mode.

 

[PC12Driver]

If the gauge is reading 140*, then it isn't the HVAC system or heater core. Even if the fan clutch was locked up the engine would still warm up. About all it could be is a bad t-stat.

 

[SheldonBates]

Mike,

Thanks for re-posting your 5-28-2013 post about the ZEP cleaner for flushing the heater core. It's on my to-do list now for my old '96. An excellent tip!

 

[DGamelin]

I think you could take fan off but I am not the only driver we never know what way it is headed and if someone wasn't paying attention it could lead to another problem. I have only seen the temp come up to 190 once. I don't think the thermostat is even opening. It has had two cummins 190 thermostat in a row. I was hoping someone has dealt with this. A couple of years ago we had a customer how said he had replaced every thing including the heater core and could not get good heat. I never worked on it just thought he missed something. My dad had a 2000 then and the heat was always good.

 

[NIsaacs]

Did you install the thermostat's, were they stamped 190-192-195*? Is the seal missing or maybe Dodge sold you a 5.9 gasser t-stat? Does the t-stat have the by-pass restriction on the bottom. It has to be a t-stat issue to not warm up while driving.

Nick