I have never replaced the cap.

No, the Hoses are not rock hard. I can pinch them just a little bit. plenty of pressure in them.

Yes, the small hard plastic one. It leaks at the fill tank from built up pressure. There's no hole or crack in the tubbing.

Side Note: Noticed white smoke coming from the tailpipe. Looks as if a Head Gasket is blown. Can this prevent the heat from working? And - Should I do the head Gaskets before anything else?

Matt

 

coolant spewing out of small hose right inside the radiator cap is normal.
Note-
It must just spew.
If it has gaps in spewing, then those gaps are air coming out.

 

Losssen the clamps going to your heatercore and have someone start the truck.
see if you have preasure in and out of the heatercore.
if someone use any of those water sealers they love to sit in the heater core blocking them solid.
or connect both heater hoses together and see if they then get hot, if so you have a blocked core

 

While making a mess, go ahead and try to reverse flush the heater core with a garden hose. You'll see how much water can't go thru there.

 

I pulled the heater core hoses and flushed it out. It's as clean as a whistle. I also flushed the radiator, new stat, water pump, hose going from water pump to stat is also new.

Im going to have a look at the throttle body. Can it get clogged and prevent heat?

 

Don't think so. Have you looked at the air vent blend doors under the dash? Maybe one of your cables is off that moves the blend flaps under the dash? See attached. You should be able to feel the water lines to the core, should be warm.

 

do you have hot water entering and leave the heatercore?

 

No, seems cold. I went to the dealer and picked up another stat. I'll put it in tomorrow and report back.

 

Check engine light on from code P0126 can happen from a stuck open stat, while the dash gauge shows normal from 130 - 240F. If you have an auto parts store that can plug in a scanner to read codes and coolant temp, might see something. Point is that an open stat would make temps low for heater, but gauge would show normal. Can't be that cold in Chicago, with all the hot air from politicians.

 

The only codes coming up:

P1590
P0304