I have1999 GMC Yukon with barely any heat at all, especially when driving. I have a brand new radiator from champion aluminum radiators, I think a 195 degree thermostat? A new heater core, and new temp mature control actuator, also new heater hoses all through out. The hvac box seems to be hot like there is flow in the heater core with hot coolant, but out of the vents to barely any heat and driving it’s honestly just cool. What am I missing here?
1. You use question marks after making statements. Should be periods.I have confirmed that blend door isn’t stuck, I did replace the actuator with one from my gm dealer, and it operates with no binding, cooling system is full and completely bled of all air, I do indeed have the heater control valve since mine is an suv, I’m completely at a loss of what to do?
2. Having LESS heat when driving reminds me of my truck. 30+ miles at highway speed, and I had to wear a snowmobile suit because the cab was still so cold. Replaced heater core, added 205-degree thermostat. Nothing helped, so I ignored it for a few years. Wasn't the heater at all--it was a rotted foam gasket, between the metal cowl structure and the plastic of the air inlet above the HVAC blower motor. Bleeding so much cold air into the cab that the heater--which was working just fine--couldn't keep up. The tell-tale was SWMBO stuck her hand under the passenger-side dash, and felt the cold draft. Had to remove the steering column, disassemble the dash to get at the gasket. Replaced the GM foam with home-improvement store foam tape. Been good for almost a decade now. (Except for needing a new thermostat years later.) And of course, it gave me an opportunity to pick all the pine-needles out of the evaprator core.
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Replaced ALL the foam gaskets with the same foam tape, while I had all this apart.
3. What is the actual temperature of the air coming out the vents?
4. Do you truly have a 195 thermostat? Sounds like you're guessing at the thermostat rating. What temperature is the dash gauge indicating? I had the clue that my thermostat failed when the gauge took forever to get 1/4 above the "cold" peg.
5. You say the heater control valve works without binding. Are you testing it with vehicle vacuum or by pushing the lever on the valve itself? If you're pushing the lever...have you checked for proper vacuum to the valve port?
6. As asked prevously--do you have good airflow at the vents? This is not a matter of the cab being cold because there's not enough air...right?
7. The quick-coupler for the heater core is restricted--intentionally--but I don't know how it could be "damaged". Might be plugged, though--but then the heater box wouldn't be hot.