2nd Gen Non-Engine/Transmission Heater works but only gets warm?

[jduval]

The heater in my 01' doesn't get as hot as it used to. Checked fan side of heater core and theres no blockage, also flushed heater core (has good flow) , and the thermostat sems just fine. Has anyone had this problem or do you have any ideas.



Thanks

 

[PBJ2500CTD]

Did you disconnect the heater hoses that go to the heater core and reverse flush the the core? What does the temp gage read when fully warmed up? Is it now reading lower that in the past? If so the t-stat may be the culprit. Then there is always the temp door in the heater box or the temp controller in the dash. Improper mix of anti-freeze? Under the right conditions if you do not have sufficient protection the AC can freeze the heater core.

 

[DFerverda]

I tried everything to get my heater hot, no heat for a long time then it was just warm. I finally put in a new heater core (and evaporator while i was in there) for the ac. That fixed it.
I too had good flow from the core, but the way the core sits in the box, i think the bottom of the core was full of ? and not letting the hot water circulate to heat the whole core.
It now will run you out of the truck on a 0 degree day after 2-3 miles.

Check the easy stuff first as described above, keep your old thermostat in the new box for backup if it doesn't help.
The R&r of the core is about 6-8 hours to pull the dash and get it back together.
Dirk

 

[Hammer]

I had the same issue last Fall when we redid my head and used a thermostat from NAPA. It would never allow the motor to reach the proper temp and when the air got cold outside it only threw cool air at best and never got warm. a simple change back to the proper thermostat from Cummins and the issue was resolved... . Andy

 

[diesel DOG]

I tried everything to get my heater hot, no heat for a long time then it was just warm. I finally put in a new heater core (and evaporator while i was in there) for the ac. That fixed it.

I too had good flow from the core, but the way the core sits in the box, i think the bottom of the core was full of ? and not letting the hot water circulate to heat the whole core.

It now will run you out of the truck on a 0 degree day after 2-3 miles.



Check the easy stuff first as described above, keep your old thermostat in the new box for backup if it doesn't help.

The R&r of the core is about 6-8 hours to pull the dash and get it back together.

Dirk

same here they load up with crap and quit working. Big job to replace