'91 Explorer Temperature Guage Fluctuation
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'91 Explorer Temperature Guage Fluctuation
I have a '91 Ford Explorer that I've changed the thermostat on and now it will rise to way past the mid-mark and then drop rapidly off to the one fourth mark. It then repeats the process again and again and again. It NEVER stablizes.
I used a meat thermometer in the heating/cooling ventilator and the temperature seems to go up and down with the temperature guage.
Right after I put the thermostat in the truck developed a leak in the water pump and the radiator. Could that be caused by too much pressure?
The mechanic has now replaced the thermostat again and it still does the same thing.
Any suggestions?
I appreciate your help.
Thanks,
Woody Williams
I used a meat thermometer in the heating/cooling ventilator and the temperature seems to go up and down with the temperature guage.
Right after I put the thermostat in the truck developed a leak in the water pump and the radiator. Could that be caused by too much pressure?
The mechanic has now replaced the thermostat again and it still does the same thing.
Any suggestions?
I appreciate your help.
Thanks,
Woody Williams
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Joined: Feb 2001
Posts: 159
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'91 Explorer Temperature Guage Fluctuation
My 95' had the same problem. The constant cycling of temperature on your engine is not good over the long term.
Someone on this board suggested that the voltage regulator to the instrument panel could cause this, but I found that the other gages were stable. A faulty radiator cap can cause internal boiling and rapid temperature changes.
I first replaced the thermostat. No change.
Then I flushed the system with Prestone Super Flush. That helped somewhat, but only reduced the temperature at which the flucuations took place.
I finally replaced the radiator with a new one bought from a local radiator shop. That fixed it for me.
If you buy a new radiator, I suggest that you get several quotes. I purchased one made by Modine. It is identical to the original factory part. I priced the Modine model at Kragen, Autozone, CarParts.com, and Napa Auto. The prices for the Modine part varied from $234 to $315, but the local shop sold me one for $165 plus tax.
Good luck, borland
Someone on this board suggested that the voltage regulator to the instrument panel could cause this, but I found that the other gages were stable. A faulty radiator cap can cause internal boiling and rapid temperature changes.
I first replaced the thermostat. No change.
Then I flushed the system with Prestone Super Flush. That helped somewhat, but only reduced the temperature at which the flucuations took place.
I finally replaced the radiator with a new one bought from a local radiator shop. That fixed it for me.
If you buy a new radiator, I suggest that you get several quotes. I purchased one made by Modine. It is identical to the original factory part. I priced the Modine model at Kragen, Autozone, CarParts.com, and Napa Auto. The prices for the Modine part varied from $234 to $315, but the local shop sold me one for $165 plus tax.
Good luck, borland
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'91 Explorer Temperature Guage Fluctuation
I too had the same problem with both a 91' and 94' Explores. Changing thermostats a few times didn't help either. What it turned out to be was nothing more than lose and slightly corroded terminal wire clip that attaches to the temperature sending unit. After cleaning and "squeezing" the terminal clip a little with pliers I was able to get a nice tight connection on the sending unit. After that, the temperature gauge read steady. This may not fix your problem, but sometimes the simple things that are overlooked does.
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'91 Explorer Temperature Guage Fluctuation
Just found a Technical Service Bulletin of Sept 97 for 1994-1997 Explorer (also includes Aerostar and Ranger). Anyone familiar with this?
Stated issue: " A thumping noise or temperature gauge fluctuation may occur on some vehicles. This may be caused by the water pump delivering an uneven flow throughout the engine."
Stated action: " Replace water pump and gasket with revised water pump (F7PZ-8501-AA)...".
Anyone know if the newer built cars have the above revised pump or is this a special pump for this application?
borland
Stated issue: " A thumping noise or temperature gauge fluctuation may occur on some vehicles. This may be caused by the water pump delivering an uneven flow throughout the engine."
Stated action: " Replace water pump and gasket with revised water pump (F7PZ-8501-AA)...".
Anyone know if the newer built cars have the above revised pump or is this a special pump for this application?
borland
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