So my mother in law has a 2001 ford escape 2wd 4cyl that I’ve been working on. Once the car warms up the heater blows cool to VERY slightly warm. No hot air ever. I replaced the thermostat, no change. Then I noticed one of the heater core hoses was hot and the other cool to slightly warm, so I replaced the heater core (horrible job) and still no change. The heater core hoses are still the same (one hot, one cool). What else could cause this? It is full of coolant and never overheats. Side note, It has a pressurized coolant reservoir but when I opened it with the car hot it doesn’t seem pressurized. Thought that was odd.
There’s a component in the vent system called a blend door.
The blend door is what controls if cold or hot air enters the cabin.
Tester
Ok how can I test the blend door? I see the mechanism moving behind the glove box when I switch it from cold to hot but don’t really know to tell if the door is working. Is there a way to force it? Would the blend door cause one of the heater core hoses to stay cool?
I do see a door being opened by the heater control valve as the heat is turned on and off, that would be the blend door would it?
In as much as the return hose is not hot, would think there is some obstruction somewhere. Just throwing out this idea for people more knowledgeable than me. Where the return hose goes back to the engine, could that be clogged or one of the metal coolant pipes be restricting the returne water flow?
my taurus of that era had a steel H bypass hose on the firewall leading into the heater core. is there any type of listing online for a bypass assy for your escape? i think the escape is a mazda creation/clone so maybe they do it differently in japan