Heat woes continue...

[Ozymandias]

Dont care about the engine in the link, that doesn't matter.

 

[MarkEagleUSA]

According to this https://www.moparpartsgiant.com/par...-heater-plumbing-heater.html?Diagram=00i68958 then the lower one is the inlet and the upper is the returnline.

And yes was pretty hard to find with google.

That diagram is for a 5.9 gasser. This one:

https://www.moparpartsgiant.com/par....html?Filter=(E=ETC;T=DGP;M=SLT+Quad+Cab+4WD)

is for the diesel and shows upper=inlet unless I'm misunderstanding something.

 

[MarkEagleUSA]

... for the diesel and shows upper=inlet unless I'm misunderstanding something.

Since the core lies horizontal instead of vertical it probably doesn't matter what inlet/outlet are.

I didn't get to flush the core today; may have some time tomorrow as I'm off work for a couple of doctor appointments but the weather is supposed to be iffy. If I don't get it flushed again, I'll see how it behaves during the week. It's not supposed to go below high 20's all week (might even see 50's next weekend).

To be honest, this is the only real complaint I have with this truck since I bought it back in March. Decent heat (especially defrost) is necessary for our crazy New England winters.

 

[mwilson]

I think I would try a Cummins thermostat first....cheap and easy to change. Might not be closing 100%......or opening a little before it should...

 

[MarkEagleUSA]

I think I would try a Cummins thermostat first....cheap and easy to change. Might not be closing 100%......or opening a little before it should...

Is Cummins 5292744 the correct part number?

 

[mwilson]

I just wonder how responsive the coolant temp gauge is on the third gens, especially if the thermostat was having occasional quick spells where it might be opening a little and then closing back up...

 

[mwilson]

I’ll check in a minute, on my iPhone right now.....I’ve run Quickserve on it before but not really all that much fun...

 

[mwilson]

Is Cummins 5292744 the correct part number?

Using an ESN from an '04 Ram that's exactly the same part number that I come up with.

 

[MarkEagleUSA]

Using an ESN from an '04 Ram that's exactly the same part number that I come up with.

Thanks... I'll see if I can find one locally today.

 

[Ozymandias]

Since the core lies horizontal instead of vertical it probably doesn't matter what inlet/outlet are.

I didn't get to flush the core today; may have some time tomorrow as I'm off work for a couple of doctor appointments but the weather is supposed to be iffy. If I don't get it flushed again, I'll see how it behaves during the week. It's not supposed to go below high 20's all week (might even see 50's next weekend).

To be honest, this is the only real complaint I have with this truck since I bought it back in March. Decent heat (especially defrost) is necessary for our crazy New England winters.

Well we can say that there is definitely something wrong with your heater system because I do winter travel far behind the polar circle and there it is really really cold. Below -30°C and the cabin is always cozy warm.

 

[MarkEagleUSA]

Well we can say that there is definitely something wrong with your heater system because I do winter travel far behind the polar circle and there it is really really cold. Below -30°C and the cabin is always cozy warm.

I know I'm getting softer as I get older but this is definitely a problem.

 

[mwilson]

A couple more thoughts before I get ambushed in the office.....

And this needs to be said.....I HATE cold rides in the winter. I will not stop until I have the level of heat I desire....this morning I rode the 63 miles to work in Hoopty wearing jeans and a short sleeve t-shirt at 1 degree. That's how I want it, no hats, gloves, jackets, etc. while I'm in the vehicle....
Climate control and a heated seat.....I'm happy!!

So I feel your pain and aggravation.....

If it was the heater core then the heat would not come and go, it would just suck all the time.....

So...the below applies with the assumption that you correct as far as heater door operation.....

(1) Check your coolant mix, too much antifreeze is just as bad as not enough. You want to be at -25 below or 50% for the coolant to flow through the core correctly. I prefer checking with a refractometer now instead of a floating ball test. Some of the newer coolants will give a false reading using a floating ball tester. I've seen it and proved it to customers...

(2) I've seen this probably four times in my lengthy career....the water pump impeller slipping on the shaft....which creates a no flow situation as there is no pressure to force the coolant through the heater core. The huge capacity of the cooling system may be hiding this, especially if it is intermittent...

 

[MarkEagleUSA]

If it was the heater core then the heat would not come and go, it would just suck all the time.....

That's what I thought, but when I first flushed the core a few weeks back it made a huge improvement. Good, but not great (no short sleeves in my cab... yet)!

So...the below applies with the assumption that you correct as far as heater door operation.....

As said, everything other than the floor/defrost mode door appear to be functioning properly. I'm confident about the recirc and blend doors which at all that matter in terms of hot/cold.

(1) Check your coolant mix, too much antifreeze is just as bad as not enough. You want to be at -25 below or 50% for the coolant to flow through the core correctly. I prefer checking with a refractometer now instead of a floating ball test. Some of the newer coolants will give a false reading using a floating ball tester. I've seen it and proved it to customers...

I'm not sure what a refractometer is, where to get one, or how to use one.

(2) I've seen this probably four times in my lengthy career....the water pump impeller slipping on the shaft....which creates a no flow situation as there is no pressure to force the coolant through the heater core. The huge capacity of the cooling system may be hiding this, especially if it is intermittent...

The pump and t-stat have been on top of my list for a while. It certainly seems like a flow problem to me, especially since it goes cool-warm-cool-warm.

 

[jgillott]

I hate to keep bringing this up, but I still keep coming back to blend door/control head/actuator issues. I've just had this happen so many times exactly the same way that I'm going to be shocked if it ends up being something different.

 

[mwilson]

I'm not sure what a refractometer is, where to get one, or how to use one.

Easy Peasy......for the time being just take a sample of coolant with you and stop at a truck or equipment dealer. See if they will test it for you, only takes a drop or two.

I purchased two from CAT for the shop to use, but for me I just bought a cheaper version.

I bought this one on Amazon, it will also do battery acid. Some of the newer ones will do DEF as well....

https://www.amazon.com/Antifreeze-R...3?s=industrial&ie=UTF8&qid=1513607207&sr=1-13

 

[mwilson]

I hate to keep bringing this up, but I still keep coming back to blend door/control head/actuator issues. I've just had this happen so many times exactly the same way that I'm going to be shocked if it ends up being something different.

You may well be correct, where it is an intermittent condition makes it a real bear......

 

[MarkEagleUSA]

I hate to keep bringing this up, but I still keep coming back to blend door/control head/actuator issues. I've just had this happen so many times exactly the same way that I'm going to be shocked if it ends up being something different.

I started with this. I knew the recirc door was bad and finally replaced it as that could be done without any major disassembly. I then did troubleshooting on the blend doors as that was the most logical reason for the issue. After taking apart the lower dash and actually watching the actuator and door movements, combined with the fact that you can hear the doors hit at full travel in either direction, I do not believe they are a problem (yes, I know I can't be certain without removing the HVAC box). Combined with the fact that the first flush of the core made a big difference, I've been focusing on flow issues.

 

[MarkEagleUSA]

(2) I've seen this probably four times in my lengthy career....the water pump impeller slipping on the shaft....which creates a no flow situation as there is no pressure to force the coolant through the heater core. The huge capacity of the cooling system may be hiding this, especially if it is intermittent...

One thing I've noticed... the few times I've had the radiator cap off and the truck at operating temp, the "flow" at the top of the radiator doesn't seem as strong as in other vehicles I've had.

 

[jgillott]

You may well be correct, where it is an intermittent condition makes it a real bear......

Yes, and it is extremely frustrating. We have a local shop here, Graft Sales and Service that does my HVAC programming work. They used to be a full line Chrysler dealer until they were forced closed during the Chrysler restructuring.

Basically what has happened to my '07 twice now (besides 2 rounds of broken doors) and now my 2010 1/2 is that for whatever reason, the control head loses its calibration for lack of better terms. When you turn your control to hot, it may move the actuator correctly, move it too far/little, or move it briefly and then allow that actuator to move back, causing the air to go cold. Whatever they do to reprogram it, resets the limits in the head and corrects this issue, provided of course that the doors and actuators themselves are operating properly. Before I would throw any hard parts at the cooling system in that truck, I would seek out a place to hook it up to the computer and at least confirm that everything on the control end is working correctly. I know it's hard to pay for shop to to check something that may or may not be the issue. But, as many times as I've had this happen, it makes sense to me for it to be the first step.

 

[jgillott]

I started with this. I knew the recirc door was bad and finally replaced it as that could be done without any major disassembly. I then did troubleshooting on the blend doors as that was the most logical reason for the issue. After taking apart the lower dash and actually watching the actuator and door movements, combined with the fact that you can hear the doors hit at full travel in either direction, I do not believe they are a problem (yes, I know I can't be certain without removing the HVAC box). Combined with the fact that the first flush of the core made a big difference, I've been focusing on flow issues.

I understand and please don't get frustrated with me by bringing it up again. I just have been through what you are going through now and could't believe it myself that it a programming issue could create this situation.