1995 ford explorer temperature gauge problem

[jmccart]

i bled it that way today, replaced the tsat again with a ford one, changed the gauge sending unit, ran some rad flush through it then drained it and refilled the cooling system, heat is better, gauge doesnt fluctuate as much but still noticable and way more then normal, heats better but still cools off, one heater core hose is hot one mildly warm im thinking there might be a build up inside the heater core

 

[96eb96]

i bled it that way today, replaced the tsat again with a ford one, changed the gauge sending unit, ran some rad flush through it then drained it and refilled the cooling system, heat is better, gauge doesnt fluctuate as much but still noticable and way more then normal, heats better but still cools off, one heater core hose is hot one mildly warm im thinking there might be a build up inside the heater core

My next step would be to flush the radiator and heater core. Be sure to use a low to medium pressure with a hose. A full blast garden hose in a clogged core is a disaster. I'm also wondering if your heater control valve is flaky. Maybe bypass it with hose joiners to see if it makes a difference.

also, these trucks need a few thousand miles to get all the air out of the system. It even says so in the manual that they may bleed up to 8oz of coolant in 7500 miles!

 

[96eb96]

i bled it that way today, replaced the tsat again with a ford one, changed the gauge sending unit, ran some rad flush through it then drained it and refilled the cooling system, heat is better, gauge doesnt fluctuate as much but still noticable and way more then normal, heats better but still cools off, one heater core hose is hot one mildly warm im thinking there might be a build up inside the heater core

Flaky heat on these trucks can also be a crappy blend door. That is another story.

 

[craigger]

i have heard that there is a coolant bypass kit to let more water flow though because there is not bypass on the water pump, can't seem to find it though. the system is said to rely on the heater core for circulation before the stat opens. Don't know if this is true. I have the same problem, fluctuates from 1/4 to 1/2 guage reading no matter how far you drive it or where the heater is set.

 

[92xlt4x4]

so i have a 92 xlt 4x4. I had to change the freeze plug on the back of my engine. i can actually do a simple write up on this if necessary. But my temp gauge is doing the same thing. I believed i bled the system properly. I also changed the thermostat before this freeze plug went bad.

So it heats up and seems like my thermostat opens up and the it goes down. Hangs out at the lower temp then goes up again. This is really frustrating. Let me know if any of these things listed have helped with this.

 

[o113attitude]

Hey
Try and reverse the flow direction on you heater core and see what happens. Would like to know if this helps. It is easy to do and it seems to have fixed my guage fluxuation!
I think it may be because water is constantly flowing through the heater core and when the thermostat closes it creates a hot/cold spot right behind it, which is where the temp sender is. Dont understand it completely but I found it by mistake last night while flushing some crap out of my heater core.
Let me know if it works please!
Thanks

 

[dfb]

I think YOU still have an airpocket in there...I just did my waterpump and it was doing the exact same thing.... After a few trips, it must have burped... Now it runs with the heater hot and the guage only moves slighty...

 

[dfb]

My gauge is still fluctuating..... I don't have any Normal word in my cluster. But if it were numbered between 0-10 and 5 being in the middle, it fluctuates between 3 and 5.... I am thinking HEAD GASKET!!!! Very slight ONE WAY leak ... it only leaks HOT AIR into the coolant, it goes past the radiator cap, into the hose and into the coolant bottle... Then it cools off, and the cycle starts all over....anyone try the block tester yet for exhaust in the coolant????

 

[elliswife]

Gauges

I still have hella fluctuation and the system is working right...the gauge just isn't. I even replaced the thermo against just for safety. My mechanic said something about the actuator in it going bad in these (the cluster gauge actuator). I had the radiator tested for hydrocarbons (aka exhaust from the head gasket leak) and the blessed little thing passed the test. He thinks my gauge is just on drugs. Everything else works well and it's passes pressure test too. Who knows.

 

[96eb96]

My gauge is still fluctuating..... I don't have any Normal word in my cluster. But if it were numbered between 0-10 and 5 being in the middle, it fluctuates between 3 and 5.... I am thinking HEAD GASKET!!!! Very slight ONE WAY leak ... it only leaks HOT AIR into the coolant, it goes past the radiator cap, into the hose and into the coolant bottle... Then it cools off, and the cycle starts all over....anyone try the block tester yet for exhaust in the coolant????

believe it or not .. there was a tsb to address this issue. They replaced the gauge, sender, and added a bypass kit. I talked to a ford engineer once about this and it has to do with steam formation, an overly sensitive sender and gauge, weird bypass system on the 4.0 and slight heater core blockages.

Replacing the sender definitely will help.

Some cars have slight delays built into the cooling gauges. Some movement around the temperature symbol IS PERFECTLY NORMAL, especially on the low end. If heat fluctuates flush the core.

If you had a bad HG, you would have no heat, and violent swings from full overheat to cold. Also, nothing you do to the cooling system would make a difference.

These engines are very reliable. If it does not overheat, it is unlikely there is a problem.

 

[elliswife]

Mine goes over the middle mark but stays within the normal range. I had my system checked for HG issues. It passed the pressure and the hydrocarbon test. Still I get crazy fluctuation. My mechanic said it was the cluster it's self and that it's common.

 

[elliswife]

Oh yeah, replaced intake gaskets, radiator and everything else but heatercore/HG but both work and don't leak. That's why mechnic says gauge is funky. Even did sender.

 

[96eb96]

Oh yeah, replaced intake gaskets, radiator and everything else but heatercore/HG but both work and don't leak. That's why mechnic says gauge is funky. Even did sender.

Movement around the temp symbol/middle mark is fine. You know when the stat opens and closes. Actually, most cars will show some movement on the temp gauge, albeit slight. I personally like to see some gauge movement. Your oil gauge is actually a dummy gauge to show two states.

The gauge is definitely something mentioned in the tsb. I believe they were updated. Your fuel gauge has logic to smooth out sloshing and movement of the float. Could you imagine if it didn't!

 

[elliswife]

Movement...

Mine isn't a little movement. It switches back and forth between the N on the NORMAL and the A or L.. It doesn't soar above it but it does go back and forth. No clues. They pressure tested the damn thing and checked for hydrocarbons and they find NADA. I have no clue. HOWEVER we do have a new developement. My NEW yes, NEW radiator had some defect in it and started leaking like a seive yesterday. Its back in the shotty shop who did it (no choice since they are the only ones who warranty it) and it's being replaced. Will the plastic separating from the core in it cause fluctuation before it ultimately failed? I'm curious.