1997 ford explorer overheating but no gurgling and cools back down when heater is turned on . not loosing any coolant. does not seem to do it at idle but as soon as you start moving it goes up and when it starts getting really hot you can turn the heat on and it goes back to around normal only slightly going up at lower speeds

Gurgling when shut off could be (as on my car) the radiator's overflow bottle feeding back into the radiator as it cools, or still boiling into overflow bottle if very hot.
Heater hose should be renewed ASAP as coolant loss may be causing overheating / gurgling and will likely cause major damage to engine if left unfixed.
Is hose cracked?
Might just need re-sealant and hose-clamp.
If you seal allow several hours to set completely otherwise steam pressure could push wet sealer out.
Is this helpful?

a blown head gasket

Well yes and no. The gurgling sound is air in the cooling system moving thru the heater core. The cooling system is not full of liquid coolant.
As for the cause of the coolant loss, if you fix the external leak and you continue to loose coolant, the head gasket could also be leaking.

Most common cause is a internally plugged radiator.
The water and coolant often react negatively to the metals and rubber inside the passageways to clog the radiator over time. If you wish to try to "reverse flush " it yourself, ask "fixya".
Other causes may be: Stuck thermostat, plugged fins of radiator outside, water pump slipping or starting to fail by "freezing up",
loose or slipping serpentine belt, and problem with the engine cooling fan.

Sounds like the thermostat is NOT functioning, since when its removed you can (apparently) fill the system. So ... replace the thermostat.

Bleed the system as follows:

1. Fill the radiator. Put on the cap, then squeeze the top hose 6 times. You'll likely hear some coolant gurgling.

2. Remove the cap, top up again.

3. Start the engine and let it idle. In about 5 minutes or less, the thermostat will open and the coolant level will lower. Turn off the engine. Go to Step #1.

4. You likely need to do this 2 or 3 times, till the gurgling stops, and you are done.

It's probably air locked. This isn't uncommon when you do work on the cooling system. Simply leave the rad cap loose for a couple days while you drive. Keep the heater turned on as well. Check the rad for coolant level and keep it topped up and your temperature should settle down. Then tighten the rad cap. Hope this helps.

I will start with the basics here first, i.e. Your cooling system needs to be properly filled.
A low coolant level will give you peaks and valleys in temp readings because the sending unit is not in constant contact with the coolant; it is just splashing on it (like dipping your finger in and out of a cup of hot coffee). For best results the sending unit needs to be in constant/direct contact with the coolant to measure its temp.
To fill your system:
Start with a cool engine and have everything you may need ready i.e. funnel, coolant, helper to rev engine.
Try revving the engine up to 2000 RPM's while topping off the radiator, then put radiator cap on while still revving engine. Return to idle.
Make sure your overflow tank is not too low either.

If that is not your problem then let's look deeper.

What color is your anti freeze? Factory "orange" is not good in my opinion.
Orange coolant can gel-up and clog your heater core.
You may need to purchase a "cooling system flushing kit" or pay to have it flushed out.

Do not reuse orange coolant. Revamp it with either the old green stuff or ask your parts man what's best.

This happened to my 1996 s10 blazer; turned out to be a restricted heater core.
My heater made a gurgling sound at certain rpm's, and did not heat well at all.

I flushed it out (the whole cooling system) following the instructions on a acid based flush kit and refilled it with the green coolant.
After the flush the gurgling sound was gone and I could not believe how much it improved the whole system; especially how hot the heater blew.

My blazer came with the orange coolant from the factory.
I was told if your level gets low with orange, it will thicken up.

I would also check for any kinks in your heater hoses just as another possibility.

Good luck!

Allow it to cool down and refill system while running with heater on hot. Hopefully this will get the air out of the system. However, if this condition persists, have the radiator checked for hydrocarbons. These engines are sensitive to overheat and you may have blown a head gasket. (hope not)
Good luck!

cool air and overheating point to low coolant level. Do you have a bleeder valve near the thermostat? You may have air trapped in the system. If no air trapped, the radiator may be plugged up not allowing proper circulation of coolant.

You most likely have air in the system. These things can be a royal pain to get the air bleed out of the system.
Look back next to the brake booster and you will see a rubber tube with a screw cap in the end of it(this is the heater bleed), also on the front of the intake area you will see a black tube with an allen sloted cap.
Remove the slotted cap and screw the screw cc on the rubber tube. Add coolant to the coolant jug allowing the system to equalize until no more coolant can be added. Add as much coolant as possible to the engine fill( the sloted cap near intake). The heater air bleed will remain open.Replace the engine fill cap.Start the engine and turn the heater to MAX position.Close the heater air bleed when a steady stream of coolant comes from it, during engine idle. Allow the engine to idle for five minutes, add coolant to the degas bottle as needed to maintain the cold fill MAX mark.Reopen the heater air bleed to release any entrapped air and close again. Maintain engine speed of 2,000 rpm for 3-5 minutes or until hot air comes from the heater.Return to idle and verify hot air is still coming from the heater. Set the heater temperature setting to 75° F and allow the vehicle to idle for two minutes.Shut the engine off and allow to cool.After the engine has cooled, add coolant to the degas bottle to bring the level to the cold fill MAX mark. This should have the air out of the system.