Temperature Gauge Fluctuating

[ratterrier]

Hi guys,

The temperature gauge on my '96 Explorer has been wavering a lot lately. A typical scenario is I'll start up and begin to drive, and within a few minutes the gauge is almost pegged to the max. The check gauge light comes on. Then the needle will drop back down to the cold side, probably where it should be. The needle will rise back up, still too hot but not as far. And at some point it seems to level out somewhat, and at this point I can't tell you if turning on the heater has any effect on what's happening.

Has anyone experienced this ?? It would be hard to imagine my engine heating and cooling so quickly. Could it be something as simple as a faulty thermostat ??

Thanks,
Richard

 

[BradE.]

Have you done any cooling system work recently?

Could be a few things. I would start with the thermostat, they are cheap and easy to replace. You might also want to pick up a new radiator cap while you are at it.

 

[MontanaGT]

I had the same exact problem.

I replaced the Thermostat and the problem went away.

 

[joe doe]

erratic meter

i had that same problem on 2 explorers now .0ne a 97 and my new 2000 just did it too.replace the thermostat and the problem will go away .........

 

[eclipse5302]

Thats crazy, I've got the same problem on my 91. I was thinking of changing the thermostat tomarrow...I guess that's a good idea.

Jason

 

[4x4Explorer23]

Hey BradE, just a question- I have heard other people says this but how can getting a new radiator cap solve or help solve the problem: I was just wondering on that. Thanks!

 

[Redrig]

me to but i failed to change mine and it overheated for good so dont wait

 

[jimbo74]

the radiator cap and the thermostat work in conjunction with each other.... They system releases pressure through the cap itself which will cuase the water to flow or not to flow based on system pressure.... that is the best i can explain it, i hope that makes sense.....

 

[Exploder99]

I had the same problem on my car but it wasn'y consistant. at first i just thought that it was an issue with the cooling fans but then the symptoms pointed more towards the T-Stat. the guage would fluctuate from hot to cold, the fans would kick on at all times, but when i noticed my oil temps getting high as well then i knew something was up. so i changed the t-stat and flushed the system really well just incase there was a blockage and all is normal ever since. infact, now i have cooler operating temps.


FYI: Do NOT mix green coolant with orange, purple or pink! (g11,g12, etc). it will turn into a brown sludgy gel and clog up everything.

 

[BradE.]

What Jim said

The radiator cap keeps the pressure in the system, if it's not getting consistant pressure, it can lead to a dancing temp gauge that will move with the pressure changes.

 

[ratterrier]

Thanks for all the advice. Unfortunately I also recently spotted a leak...coolant, of course. Not having a good place to dispose of coolant and flush chemicals, I let Goodyear do a flush and fill. Head gasket was leaking..the Goodyear guy seemed to think putting in a sealer should take care of it. Don't think leak's stopped yet...but truck has only gone 75 miles since.

And the temp gauge still moves between cold and midpoint. I picked up the cap and thermostat and will replace cap today and thermostat this weekend.

I had written a new post about this since the topic became more severe.

Thanks again...

 

[Makahveli]

Funny thing with my ex is that the oil temp starts up at about 3 quarters when starting it in the moring. and then eventually the coolant temp rises high a well. when i stop and go the fluctuate opposite of each other but styll above mid-point. then again it could be the gauge . my voltage meter is staying around 10-11volts while driving. Lacks a bit of power now when going up hills is the only difference. Can the thermastat really affect that?

 

[VirginiaMonkeys]

I had the same problems.

My guage would start fluctuating after a few miles of driving. It would run all the way to the right, way past the overheat point, then come back to normal.

I replaced the thermostat and the rad cap. (Don't forget to get a thermostat gasket when you do this. I had to make 2 trips.) I let the air out of the system 3 or 4 times.

Finally, I had someone diagnose it and he replaced the guage in the dash for $430 and it solved the problem. But the radio won't come on now and the brake light stays on.

I could have done better for $50 doing it myself I guess. Oh well. Problem solved and no major engine damage.

 

[scotts95xlt]

Mine kind of does the same thing, except my gauge never makes it to the midway marker, when I accelerate it drops back to the bottom of the normal range. Under steady driving it stays a tad above the normal marker. Should I change my thermostat?

 

[prybylo]

I also had problems with temp gauge fluctuation. Actually it wasn't the gauge - the temp of heat was also inconsistent. It was under warranty so I took it to the dealer - they replaced thermostat, but this did not fix the problem. After that they insisted that there was no problem, so I replaced it myself with a NAPA thermostat. The gauge and heat have been great since.

I think because the heater return, temp sending unit(to gauge) and thermostat are all in such close proximity, Explorers are susceptible to these flucuations. Not sure because I haven't looked at other vehicles to see if they're similar, but it just doesn't look right to me.

 

[AlaskanJack]

Same problem here a while ago I did t-stat and cap, but what really worked was adding some Royal Purple's Purple Ice to the coolant. temp dropped by a 1/4 in 24 hrs and has been fine ever since.

 

[VirginiaMonkeys]

Crap!

It worked for 3 days and now it's back to fluctuating. It's more tempermental than before though.

 

[newstang]

I have had three explorers, all had the samr problem when ever you screw with the cooleant, water pump, or thermostat.
It is air in the block. Temp rises opens thermostat then cools, cycle begins again, and again.
Fix:
put in a "T" like the prestone flush t in the heater hose leading to the block. You need to fill the engine from the top of the block.

 

[hug_army]

This just happened today, went 5 miles gauge almost pegged turned heater on it seemed to control the fluxuations.

Thanks guys you answered all my questions. I will miss the Stars game tomorrow but will put in new t-stat, rad cap and coolant.