In the two previous 99 Dodge Cummins 2500 4x4 pickups that I had, once I replaced the heater core, evaporator core, cleaned the hvac box, new 190* thermostat, new blower fan motor, both of those pickups would roast me out of the cab if I ran the heater on high for too long.

 

On this 01 Cummins 4x4, it has a new radiator, new water pump, new heater and evaporator cores, cleaned the hvac box, new heatertreater transposer for the temp blend door, new blower motor rheostat, and new NAPA 190* thermostat. The only thing that I haven't changed is the heater blower motor on this pickup, but I have good airflow and my engine temp is running 190*, but this truck will not roast me out when it gets too cold outside. I just installed a geno's garage winter grille cover over the radiator, condenser, and intercooler, but that didn't make it do anything different and the truck still runs at 190*.

 

Anyone have any other ideas to fix this issue?  I know this is a very common issue in the 2nd gen dodge pickups and hopefully someone has some ideas as what to do next to fix it.

 

Thanks!

 

Doug

 

 I have a similar issue as well. I'll be watching this one to see the outcome. I just haven't dug into mine much yet since I need to replace my radiator. I'll do a system flush then. Already have a new 190° t-stat and new heater core.

I bought my work truck used, one problem I had was when I dropped the blower motor out the 'squirrel cage fan was full of leaves. That's one thing and then IBMobile came up, from 800 miles away to do my Heater core. What a guy.. he is amazing. It does take awhile to warm the truck and get real heat. I think his wire diagram on switching the A/C compressor to control on/ off would be a good mod.

1 hour ago, Doubletrouble said:

 I have a similar issue as well. I'll be watching this one to see the outcome. I just haven't dug into mine much yet since I need to replace my radiator. I'll do a system flush then. Already have a new 190° t-stat and new heater core.

One thing I found was it does real good to take the garden hose and flush thru the heater core both directions by adapting the hose to the inlet outlet heater hoses. Much dirt comes out that way.

49 minutes ago, JAG1 said:

I bought my work truck used, one problem I had was when I dropped the blower motor out the 'squirrel cage fan was full of leaves. That's one thing and then IBMobile came up, from 800 miles away to do my Heater core. What a guy.. he is amazing. It does take awhile to warm the truck and get real heat. I think his wire diagram on switching the A/C compressor to control on/ off would be a good mod.

One thing I found was it does real good to take the garden hose and flush thru the heater core both directions by adapting the hose to the inlet outlet heater hoses. Much dirt comes out that way.

 I did that not long ago when I changed the t-stat. A year or so ago I removed the hvac box, clean it, replaced the heater core and a/c coil in there and inspected the foam seals. Didn't change alot other than no more coolant on the passenger floor. Lol

Yep Coolant on my ladies pinkies wasn't too cool when we went for nice dinner.

I pulled into my shop right after driving 20 miles home from work and left my truck idling turned the heater on high and probed the heater core hoses again. Hot side was 194* and the return side was 182*.

 

 

 Only 12° difference. I think it should be a bigger margin than that. I belive maybe in the 30° range for good heat exchange from core to air. 

7 hours ago, 01_Cummins_4x4 said:

I pulled into my shop right after driving 20 miles home from work and left my truck idling turned the heater on high and probed the heater core hoses again. Hot side was 194* and the return side was 182*.

 

 

Not much heat getting exchanged for sure. When's the last time you flushed the system and checked for tree debris inside the plenum?

 

I wish those plenums could have a simpler service access door to get in there for cleaning.

1 hour ago, JAG1 said:

I wish those plenums could have a simpler service access door to get in there for cleaning.

 I agree. Still planning on making a filter for under the plastic cowl in front of the windshield. 

2 hours ago, Doubletrouble said:

Still planning on making a filter for under the plastic cowl in front of the windshield. 

I glued screening to the fresh air vent openings.

 

 

17 hours ago, JAG1 said:

IBMobile came up, from 800 miles away to do my Heater core.

Sure did but JAG1 then helped me replace the roof on my 5th wheel.   So, we helped each other out to get some major projects done.

7 hours ago, JAG1 said:

Not much heat getting exchanged for sure. When's the last time you flushed the system and checked for tree debris inside the plenum?

 

When I replaced the heater core and evaporator core in March of 2021. I thoroughly cleaned the inside of the HVAC box.

 

I don't park anywhere near trees and mostly I park my truck in my climatized shop. 

3 hours ago, 01_Cummins_4x4 said:

When I replaced the heater core and evaporator core in March of 2021. I thoroughly cleaned the inside of the HVAC box.

 

I don't park anywhere near trees and mostly I park my truck in my climatized shop. 

Get this you guys..... @W-T Parks his truck inside a Hepa Filtered clean room. I think he even flosses his truck between parts it's so beautiful. LOL!

Dan @IBMobilenice procedure to prevent debris entering the cavity...the job of removing the core for clean up is miserable job and your example really promotes clean longevity.

 

@JAG1...Mike, I'm not that bad...or am I ? OK, perhaps I'm a bit excessive but, my Mom had me tested and the Doctor did confirm an Excessive Compulsive disorder and advised keeping an eye on me.

@IBMobile, I am bit chicken about pulling the wiper arms. What is the best way and not damage anything?

 

Do you guys mark the stop position with blue tape on the windshield and then just use hands no tools? T.I.A.

Jag, don't be afraid, but don't be stupid either.   You may have to spray lubricant a few times before trying to remove.  Try to do it without prying.   I usually have to pry them carefully.  (that is why I like most asian models, they use a stud and nut on top so you can use a puller....)    just don't pry directly against the windshield.   Just go slow and work them.  you can usually stack some plastic or wood to distribute the prying force.  ours are nice the latch "automatically" releases when you pivot them away from the windshield.

 

Clean everything up before you put it back together and use a little anti-sieze.   I don't worry about position really.  Once they are apart and you have cleaned them you can reposition easily.  So I just look at travel.   I am tall in the seat, so I like longer than stock wiper blades, so I usually have to reposition them so they don't hit the edge of the windshield.  If you like where yours are, the tape idea is a great method.

 

GL

Hag

 

 

1 hour ago, JAG1 said:

What is the best way and not damage anything?

Have someone else do it.  

 

When I set out to cover the openings, I made templets out of thin carboard from cereal boxes.  I still have the templets and can do your truck at the next camp get together.

Hey! close them off and cut holes thru the metal toward the dash to recirculate the air for great cabin heat, right?

 

Probly get shot for this idear

38 minutes ago, JAG1 said:

Probly get shot for this idear

 

 

Want to say that I also put the longest wipers on that fit the windshield and for some great reason they stopped that business of stopping in the wrong place. I really Like those longer wipers

 I pulled my wiper arms off just to repaint them. They looked horrible.  I took my time, wasn't a difficult task just be patient. 

 Now I'll be removing them again to install screens. 

 @IBMobile, what type of screen did you use? I like that idea! Also, what glue? Thanks!

I used nylon window screen mesh that I had lying around.  The adhesive, I think I used, was clear silicone sealant.