2nd Gen Non-Engine/Transmission Interior Heat

[BLassiter]

After doing some more upgrades to my truck I have seem to have lost alot of interior heat. My heat used to be able to blast me out of the truck it would be so hot but now I can keeping it full blast and barely feels like its blowing 70 F. I have removed the front fan and replaced with flex-a-lite dual fans and also a new electric transmission fan. The fans keep the rig extremely cool but I also made sure to have a 190 degree thermostat which i do. The engine will get to about 200 degrees and if i touch the main heater hose under the hood it feels extremely warm but it just isnt making it inside the cab. This all basically happened when i blew my head gasket again and had headwork done. Fire-ringed this time.

 

[EricBu12]

Sounds like a blender valve is messed up. .

 

[Bob4x4]

Our trucks do not use a water valve. I would make sure you have no air in the system,that the heater core has good flow,then make sure the blend door has full travel. Since you had good heat before the head work I would place the blend system last in the possibilities.

 

[firefighter_2000]

Vac. line

Just had to replace a vacuum line on mine causing very little heat. It runs behind the air filter box on the passenger side. Should be a white "L" fitting with a hose headed back through the firewall to the hvac box, and the other end heads over to the vacuum distribution block on the firewall on the drivers side. It takes about 2 1/2 feet of the vacuum line to replace it. I replaced mine night before last and viola!!

Craig

 

[BLassiter]

thanks ill have to check into that when i get home

 

[nutter3]

If you've never had a new heater core, I'd say yours is probably somewhat plugged up. My truck lost heat slowly over a couple winters, then I replaced my heater core after mine sprung a leak. I've got all my cab heat back now.

 

[firefighter_2000]

Agree..

Agree with nutter... If it happened over a longer period of time, could very well be a plugged heater core... If it happened just suddenly, could be a problem with the blender door. Good luck!

 

[TBurow]

i have the same issue, had poor heat and a leaking heater core, replaced core and checked blend door when it was apart, still poor heat unless on recirculated air. is there some sort of restrictor in the heater lines or am i missing something here?

 

[MarkMiller]

You can try backflushing the heater core to push out any sediment that is in there. I am in the same situation with my 99 and this weekend I will start with a check of the vacuum lines and do a flush. Just gently pull off the lines at the engine and run water through the system from a garden hose to try to flush any stuff out. Auto parts stores sell chemicals you can put in the radiator to clean the entire system followed by a flush. I have never used them.

 

[DSenn]

I have a similar problem that started when I had to get the heater core and housing replaced due to fire (I"ll recap that on another post). Now I get little heat compare to pre-fire. Had thermostat changed as it was sticking. Looks like this one is a 165 degree, but no change to lack of heat situation. I am thinking blocking door rigging, since it is almost like I am not running with the temp control on full hot.

Any pointers on where this adjustment may have gone wrong or what else this problem may be?

Thanks!

 

[Houser]

Heater core flush

I did the garden hose flush thing with mine last winter and its put out plenty of heat since.