So i decided to make one last thread about this. I still have luke warm heat, and nothing has helped. I have done the following:

Flushed entire cooling system both way for 30min
changed t-stat (195 and it works)
filled with good quality coolant to a 60/40mix
checked blend door and it works fine
disconnected ac compressor
tossed card board in front of rad..
burped ALL air out of system several times(last few getting none)

now its fairly warm right now(teens) and the heat is hardly luke warm, and when its colder its even worse. I can turn the heat off for a few min and back on and get heat, or i can put it on the recirculation and i can have pretty damn good heat. I am at a total loss of what to do. I have searched left and right and up and down on this site and others over this problem and did everything mentioned atleast once. I know i am getting good flow out of my heater core and my blend door is working great. So any ideas guys? The truck gets up to OP temp just fine and stays there but i have **** for heat. When its -20 and colder i can't even really drive it as my windows freeze up because the heat is so bad. I really need some help here guys, im about to sell her because this has been an on going issue.

 

is there any way to open up the heater box and see the blend door ?

we had an AC problem in a jeep, and using the heater/treater instructions... cut the box open with a hot knife. when we could see the blend doors and the recirc door not operating right, it was obvious what was wrong.

seeing yours might help you.

follow up questions.
1. when your truck is at operating temperature - are both heater hoses too hot to hold onto? they should be.
2. did you backflush the heater core itself, and get water flow both ways, and prove that it wasn't stopped up?

 

Heater hoses are not hot... more warm... Got water both ways. Tonight i was stupid and left a hose clamp loose and blew all the coolant out that i just bought... ****... this sucks!

 

mine was just a water pump issue, mine went out and bought one from hughes and was defective after install so called them up and they sent me a new one and then i got wonderful heat

 

-20F is -28C and thats cold, Is the motor comeing up to proper opt temp? are you using a winter front? cardboard is old school and not that great of thing to use, don't block it all the way off cut a 8" hole in the middle of the cardboard for some air flow. Way back when i lived in winterpeg we would wrap the heater hoses with pipe wrap to help hold the heat. It really sounds like a stat maybe the new one is not working right, also make sure you have the right one, someone might have put the wrong one in the box before you bought it. Just putting some ideas out there for you.

Edit: I just reread your post and the truck is coming up to temp, so water pump maybe?

 

Motor is coming up to temp just fine, yup using cardboard and that helps it heat up faster lol, tstat works fine and is good quality fail safe(and i did test it, plus it did this before doing anything), so im pretty lost at what to do. Im thinking my water pump may not be circ-ing enough water so therefor im not getting good heat to the heater core...?

 

replace the water pump i had the same issue 2 months ago.and it worked until i blew the motor and heater core

 

Sometimes the vac that operates what ducts open and close could be cracked. That will not allow for the full flow of air through the heater core. It will mix with outside air.


Have you done any work before the winter where you needed to disconnect your vac lines on the intake? Sometimes they get cracked or they are not installed correctly.

I had a problem in my 1996 where the heat would not be HOT, then I would turn the **** all the way to defrost (while on max blower setting) then back to the face setting. That worked.

 

All the lines are fine too... I think its a coolant flow issue because my heater core lines never get hot, there just warm...

 

Flush the heater core itself. Disconnect the hoses, (plug the ends you arent using, so you don't lose as much) run water both directions thru the core, until if flows good, and is clean. Go both directions a couple times, ending with backwards. Try and prevent fluid loss as you put the lines back on, they will siphon water right out of the heater core, and you will end up with the big air bubble in there anyway.... Then burp the entire system again. It should work.