Thanks for making this. The heat in my 1998 F150 4.6 blows lukewarm but not hot. I forward and backflushed it twice last year. Each time it worked for a couple of days then back to lukewarm. I'm getting getting good waterflow forwards and backwards. Worn waterpump maybe? On the dash the it only reaches just above a quarter of the way above "cold", and I've also replaced the thermostat, to no avail.
Just seeing this comment. Normally when this happens, it's a stuck thermostat or the heater core is clogged. I see that you've replaced the thermostat and flushed the heater core. It could still be the heater core. Have you found a fix for this problem?
My 1998 F-150 has 50k miles, always garaged and maintained. My problem is that the air conditioner and compressor are on even when I turn it to the heat setting. It turns off in the off position and the blend door works
Does the rear heat use the same heater core as the front. The back gets super hot, but front doesn't get hot at all. I've owned it for 4 years and it has gotten worse to the point of no heat in the front. I'm going to pull the actuator and see if it works. Then go from there.
The expedition has a separate heater core for the rear. Depending on the miles the front heater core could be clogged. A test for the heater core is to remove the heater hoses then put a water hose to one end of the heater core to see if it has good flow. Ford had big issues with there heater cores.
My temp gauge shows its just above C when usually it's half way between C and H so I'm assuming its my thermostat stuck open is why my heater is lukewarm ?
Correct. When the thermostat is stuck open it will take a very long time for the vehicle cooling system to reach operating temp. And if the vehicle cooling system does warm up your heater will not get as hot as it should.
My 2001 isn’t blowing proper heat. The blend door and actuator are working properly, but no heat. The heater core shows no sign of leaks, from behind the glovebox or any leakage on the passenger floorboard….not sure if heater core is bad or not…..I’m trying to eliminate everything possible, before it actually is the heater core….any suggestions ? Thanks
@@neighborhoodmechanic3822 for me, its a little strange. 2001 5.4l f150. Heat works good on the first 3 settings but on max it eventually becomes luke warm heat. my temp goes to operating temp, my thermostat is new. fresh coolant. only thing i can think of now is heater core
The only other thing I can think of that would cause that is a worn water pump. It’s not likely but I’ve run into it before. What happens is that the fins on the water pump wear down. With worn fins, the coolant cannot circulate properly which would cause a problem with your heat output but the pump would still work good enough for the vehicle not to overheat. Other than this you have a partially clogged heater core. A test you could run is to disconnect the heater hose at the inlet of the heater core. Run the vehicle for a couple of seconds. There should be a lot of water pressure coming out of the engine through the disconnected heater hose, if not the pump is probably worn. After that, reconnect that heater hose and then disconnect the heater hose at the heater core outlet. Run the vehicle for a few seconds. You should have have high water pressure coming out of the heater core. If not, the heater core is clogged and needs to at least be back flushed or replaced.
Is this account still active, I have a 03 f150 5.4 , there’s no heat at all I checked the blend door actuator, it works correctly , do you think it could be the heater resistor under the glove box
with the blend door actuator out, did you try to physically move the blend door to be sure that it is not binding? if the door and actuator are good, get your truck with to operating temp, feel the heater core inlet and outlet hoses to see if they are hot to the touch, if both are not then your issue is in the cooling system. heater cores are known for clogging/leaking on these year model fords. back flushing the heater core normally does alot of good. i would say to check the heater control valve but i dont think these trucks have them. A stuck open thermostat or weak water pump are possibilities as well. the resistor under the glove box is for the blower motor and will not affect the heater.
@@neighborhoodmechanic3822 no I didn’t physically move it I didn’t know you could , I seen the thing that spins from hot to cold moving so I assumed that it was good , I replaced the blower heat resistor just a hour ago , and still nothing but cold air but it you switch it over to cold. You call feel that the air gets colder ,
@@illstartAfire yea i would first make sure that the door is not in a bind, sometimes the hole that the actuator goes into will break. but if all is well with the blend door and actuator then there is an issue with your cooling system
