strange heat issue. need opinons

[checkedout]

I've been reading thru threads and none seem to match.
The last two mornings the X warms up fine, after a couple minutes of driving the heat starts to blow cool and I notice the temp guage reading a little low, then back to normal, then a little low etc. But it still blows cool air even when the gauge is reading normal. Well I stop for my coffee after about eight miles and when I get back in to continue my commute all is back to normal.

Fluid is fine
Tstat is a couple years old

 

[ronnie mullins]

Usually when the heater blows cool its low coolant or a blocked heater core.Could be a thermostatic control valve going bad[but I really don't know if the explorers have the control valves].You need to check the temp and coolant level next time it blows cold,you'll need to get a thermometer since the gauges in the explorers are are really just idiot lights.I personally would do this at home not on the road.Take a towel or something to protect your hands while removing the cap very slowly.

 

[jimbo74]

the early gens do have the heater bypass valve and they are like $70 from the dealer... about $30 aftermarket.....

 

[checkedout]

I'll check the temp if it does it tomorrow morn.

 

[wpurple]

My 97 and 99 both have the htr control valve.

 

[checkedout]

It worked fine this morning. I'm leaning towards the htr control valve going bad.