heat question

[Mark Keefer]

Has anyone ever had an issue with there heater not throwing heat when the truck temp gauge is at normal operation or even after the truck runs for 10 mins or so? I was thinking it was my thermostat being stuck open. Changed the thermostat and ran the truck till it warmed up and it still threw cold like air.



for thee record I have it set to heat setting too, not cold

 

[Chris Taylor]

Couple things to look at.



1. Plugged heater core.

2. Heater valve not working.

3. Blend door not working.

4. Water pump not pumping enough? (this one is only a remote possibility...)



Below is a link to a diagram from a sponsor's page.

 

[Dan Long]

You're not on the Max A/C setting, are you? In that mode the valve in the heater hose closes off so that coolant doesn't circulate through the heater core and you can only get cold air, regardless of your temperature setting.

 

[scott degroot]

Does the temperature of the air change at all when you go from hot to cold or vice versa

 

[Mark Keefer]

no I noticed the issue in oct of 2013, and if I stepped on it I got heat within a minute and sometimes when I got heat the temp gauge would go back down as if the thermostat was sticking. I had a really cold winter where I live and I took 2 or three road trips and my heat had to be on full or setting number 4 to keep warm and never had to turn it down or change the temp from warm to cool. also Dan, I haven't used the a/c yet rreally but I know what that does.



I1tech I was playing with that today and it took a lot longer than it should have to get the hot air to come threw. my dad (DIY mechanic) is thinking it could be the air temp control switch or maybe I have a coolant leak that we have yet to find as my coolant need to be top off. which I do later this week since my cooling system looks like it could be flushed.

 

[Bob Floyd]

A lot of explorers the heater core gets a air lock in it. Take the hose coming out of the heater core off or loose and start the vehicle and run it till coolant starts coming out of the heater core and then put the hose on with engine running. Heater core is placed very high in the vehicle above the engine so if there is any air in the system thats where it ends up.

 

[Vic Sorlie]

From your latest post it sounds like at minimum you're overdue for a coolant service. Take a look at the YouTube video from Eric The Car Guy. He's got many useful videos.

 

[Gavin Allan]

Sounds like you have a vacuum leak, or a bad vacuum check valve at the vacuum tank.

if I stepped on it I got heat within a minute and sometimes when I got heat the temp gauge would go back down as if the thermostat was sticking

Sounds like you have a vacuum leak, or a bad vacuum check valve at the vacuum tank, or something not right with the vacuum operated heater door under the dash.

 

[Mark Keefer]

I'm going to flush the syste out this weekend,,, my truck was total and I rebuilt it 3 years ago And I am a very picky person when it comes to parts an making sure no corners are cut like some people I know. original owner maintain the truck very well but there is a chance with the used parts I got is why my system could use a flush. I'm betting after reading online that since I apparently have been driving it wit low fluid is prbly the reason I have a heat issue.



As for the check valve, I have vacuum at that part. If after my system is flushed I still don't have heat I will check that door behind the glove box.. I can usually hear that door move when I play with the controls

 

[Lloyd Ledford]

a lot of explorers and rangers alike were prone to have the blend door actuator either fail or the blend door crack open where the actuator goes into it at the top. open your glove box and lower the door to hang down. with a flashlight and mirror operate the temp knob to full cold and then to full hot, try to see if the temp blend actuator motor is rotating. if it does, then the door is cracked. if it doesn't. then the actuator is probably toast. another sign of a bad actuator is a slight clicking noise that may go away with the temp knob in one direction or another.

edit-----I didn't realize your rig is an '04. i'll do some research and repost.

 

[Mark Stadnicki]

My '10 drivers side blend door actuator failed so it's blows hot when AC is on and cold when heat is on. You can hear it making a racket trying to move against it's command. Unfortunately everything I've seen on a repair requires removing the entire dash or some hack job YouTube video of cutting dash in half at the center to remove the driver?s side.

 

[Mark Keefer]

UPDATE: well I flushed the tomato juice out of my cooling system and after replacing it along with a new rad. cap my heat seems to work normal again. I couldn't believe how red it looked especially since the stuff the was put in when my truck was rebuilt was clean like but used. My cap if it was on the opposite way would leak. Thanks for all the tips though.