Temp gage fluctuation

[1993EXP]

Noob to the Ford product here,

On my 93, the analog temperature gage will slowly climb to the center position between C & H pointing straight up, then will drop back down towards "C" then climb back towards H and do it all over again and again and again

I installed a new Heater Coil with Thermostat in the spring, what could be the problem, did I not burp it well enough?

TIA
Larry
INDY

 

[LBarr2002]

both of mine have done that as long as I've had them...seems to be normal.

 

[1993EXP]

Thanks, I think this has begun recently, I and wodnering about the possibillity of my radiator being clogged, it seems like the coolant surges every so often.

Would a bad radiator cap cause this too?

 

[LBarr2002]

Like I said, mine have always done it... I've had the '91 for 7 years and the '92 for 2 years, new radiators, new caps, new thermostats, no difference. A "ford mechanic" looked at the '91 years ago and said nothing was wrong.

 

[1993EXP]

Oh well, it has 207K on it and still runs well, thanks!

 

[J. Anthony]

My '93 does the same thing and like all other posts, it just fluctuates. I have had two Explorers and they both have done it. Right now I am trying to figure out why my amp/volt guage seems to be showing a high charge on some days and not on others. Even on the days when I have my blower motor running it won't show a high charge. But none the less, runs good and never fails me.

Anthony

 

[Explorer#2]

yeah the temp guage is going to change, the harder you run the engine the more heat it puts out. and the easier you are on the engine the cooler it will run. this is simple heat transfer

 

[LBarr2002]

yeah the temp guage is going to change, the harder you run the engine the more heat it puts out. and the easier you are on the engine the cooler it will run. this is simple heat transfer

Yes...but this is not what he's talking about. The thermostat is supposed to keep the engine temperature relatively constant. But, every first gen I've ever been in the gauge moves from 1/4 up to over half way, no matter what the strain on the engine is. Just yesterday i was cruising along at about 45 with it 35 degrees outside and the temperature started rising, went a little over half, then dropped back to normal...

 

[bon_temps2000]

Temperature Fluctuation Problem Found and fixed

I ran into the problem with temp gauge fluctuation recently after I had removed my radiator (replaced condensor) and replaced all of my hoses.

As it turned out, I seem to have inadvertently swapped the inlet and outlet hoses to the heater core when I put things back together again. I wouldn't have bet that this would have made a difference, but once I swapped them back again it fixed the problem right up. My gauge was swinging from below the "N" to well to the right of the "L" and back again at 3-5 minute intervals. Also, I was getting that funky swishing sound from under the dashboard. I swapped hoses on the heater core and both symptoms dissappeared completely.

I have not been able to find a definitive answer about which is inlet and which is outlet, but right now if I stand in front of the car facing the engine I have the water pump hose going to the right port and the engine connected hose going to the left port. The temperature is nice and stable and the heater works fine.

Hope this helps.