Fluctuating Water Temperature

[Kingkobra]

This is a recurring problem in Fords in general. I'll venture a guess that your in a cooler climate now and it started when the outside temp dropped...??

rustbeltlife?? How will a coolant pressure tester show you a blown headgasket when there is no coolant loss??? That makes no sense at all....

 

[mckenzieslayer]

I have the same prob with a 94 explorer.
For four years the guage was on the O in normal, good heat anytime, ran excellent.
One day I noticed the guage going up to the A and back down below the N.
This happened for a few months and just as I was wondering what all this heating and cooling off of the engine was doing to my heads, It sprung a small leak in the left front of the manifold right behind a/c pump and p/s bracket.
Being in NY and below zero for a few weeks I would just add a little antifreeze if needed until I could get to it.
Well it didnt let me, the leak got worse after two days and it had to be towed.
Intake gaskets changed. Still had the same problem. Note: Thermostat was changed with tickle valve up , twice. MOTORCRAFT parts
Same problem.
I am also at a loss.

 

[satsuperman]

gentlemen, i think we found a very common flaw in these explorers

my 94 sport has been doing the same thing forever as did my 94 ranger with the same 4.0 v6. both had complete overhauls with all new parts. both of them had the same temp swings. never figured it out and just gave up. my ranger went to 220,000 miles before trade in with no problems and my exp sport has made it 54,000 so far. i just concluded that it was the 8th wonder of the world and dont sweat it if there is no problems. (both never overheated or had any cooling related issues)

 

[greenbeer]

My 93 did this. The problem was hair line cracks in the heads between valves. Put new heads on it, now its back to one constant temp.

 

[Alf]

I have a 92 explorer 4 liters and the weather in mexico is hot. I quitted the thermostat, cleaned the radiator but the temperature turns high in the L of NORMAL. The deposit of coolant starts to boil. Someone told me that if the exhaust system is little blocked some gases of the combustion stays in the motor and increases temp. If you have some suggestions I appreciate.

 

[gvsa123]

How is your hoses? Is there any chance one is getting sucked flat and then opens back up at higher temp as the water builds up pressure?

This symptom is present in mine. I have all the same symptoms, plus a thumping sound which I believe is being caused by this "collapsing" of the hose. Replaced the water pump and tstat already. Flushed coolant, but to no avail. Could this be causing the problem? Should they be replaced?