Cummins Diesel Forum banner

heater not heating....wtf?!?

1K views 11 replies 7 participants last post by  Bubba88 
#1 ·
I noticed last night while I was driving that my heater is not blowing "hot" air. it's almost like the outside air but a tad bit warmer. It was 26*F last night. I know something has to be wrong bc the truck was warm, and it was colder than this about 3 weeks ago and the heater blew air so hot you'd have to crack the window. I don't know jacksquat about ac units and such so I'm coming to you guys!! ANY INPUT WOULD BE GREATLY APPRECIATED!!! It was 12*F this morning and I froze my off driving an hour to work.
 
#2 ·
I would say you described a plugged up heater core. My girlfriends jeep does this all the time. You need to flush out the heater core using water or if it's to cold you can use air. I haven't done it on my truck yet, but trust me, if you don't own a pair of needle nose vise grip pliers, go to home depot, spend 5 bucks and get two needle nose vise grip pliers, pinch the hoses and remove them for minimal coolant leakage, then blow out the heater core, it works better with water but air should suffice. If it wasn't plugged you may have an actuator door problem which is a pain in the butt............
 
#3 ·
When you're flushing it out make sure to flush it backwards. You will be amazed at what you will get out of it. BTW I just got done replacing the heater core and dash pad in mine a few hours ago. It isn't the worst job I have ever done but it isn't fun either.
 
#4 ·
where is the heater core at in the truck?? i had to replace the blend door actuator in my 3rd gen beginning of this year and it was a pain in the butt taking out the whole dang dash and everything.....hope i dont have to do that...
 
#5 ·
I got the same problem but I dont want to tke the dash apart to replace the heater core and I know its plugged because the radiator had a leak so I replaced it and someone had put a ton of stop leak in the radiator. If you use warm water do you still use air to blow the water back through?
 
#6 ·
do not use air! you will jam the crud into the corners of the core

to replace it the dash has gotta come away from the firewall
plan on 4hours the first time if yur good, and 6 if yur not
its mostly phillips screws and 6mm socket
replace the core if you must
but, i have heard that one man has successfully freed the plug using liquid drano to free the clog and gently flushing backwards
doing this repeatedly

the draw back is that if the core is nearly shot any flushing will expose the weak area and the core may begin to leak, but what the hel,l you cant use it as it is anyway.
really i think i will devise a filter to mount in the hose to catch some of this stuff before it goes into the core.

the
 
#12 ·
i'm going to check that out tomorrow on my day off. ive noticed that my engine temp gauge isnt getting over 140*F. The weather has been anywhere from 15*F - 45*F.....im wondering if this has anything to do with my heater problem......:confused013:
 
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.
Top