- Joined
- September 23, 2020
- Messages
- 1,541
- Reaction score
- 2,126
- Location
- United States
- City, State
- Alabama
- Year, Model & Trim Level
- 99 Explorer XLT 4.0 SOHC
Hello everyone so I'm currently trying to figure out a heating issue in my explorer last winter I replaced the water pump, heater control valve, thermostat, upper and lower radiator hose, bypass hose, aluminum thermostat housing, and I flushed the entire cooling system out with a bottle of prestone radiator flush I also back flushed the heater core with a water hose and cleaning vinegar but my heat will not get hotter than 115F at the vents and at 2k rpm it gets to 120F blend door is fine and the heater control valve is opening all the way but for some reason I can't get the heat to get hotter and I really don't want to pull the dash especially in the cold and I really need this fixed because we are expecting a brutally cold winter here with temps as low as 8F also those temps at the vents are with a 47F ambient temp and as the temps drop outside it seems like the heat is less and less warm engine temp is staying around 85C and 90C the water pump heater control valve and thermostat is all ford OEM and the hoses are Dayco if anyone has a suggestion on what I can use in the heater core to flush it or if I'm missing something please let me know