Temperature Gauge Fluctuation

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Jan 1, 2014 | 07:51 PM

rcnease

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Temperature Gauge Fluctuation

I have a 96 F250 super cab with a 5.8L (351W) engine. There is a plow on the front with a full v-hopper salt spreader in the back. The other day when it was being driven home, the temp gauge spiked. I lowered the blade some and slowed down and the gauge came back down to a normal range. When I got home (roughly 1 mile or so from the point of noticing the spike), I checked under the hood. The overflow bottle cap was blown off and there was coolant over the compartment. I filled the bottle back up the next day to the cold level, took roughly half a bottle. Now the temp gauge seems to fluctuate a lot faster now. Not staying steady as you would sort of expect once the engine is warmed up. I have run it around the block a few different times and it doesn't heat up above the normal range during these trips, but I really don't want to get it in the heat of a snow storm and have a major issue on my hands.

Does anyone have any ideas if something is broken. I am thinking maybe the thermostat, but just not sure. Much thanks for any help in advance.

Jan 1, 2014 | 08:11 PM

timbersteel

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Joined: Mar 2005

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From: Mexico, Missouri

Perhaps t-stat is stuck closed or partially..perhaps. Coolant psi is way high as is temp. Something in coolant, passages plugged, radiator clogged.

How long since it had been flushed?
I would check radiator hose condition for weakness. Can become weak and collapse.

Jan 1, 2014 | 08:16 PM

88n94

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From: South Dakota

My first thought is that the fluid driven fan behind your radiator, attached to the water pump isn't functioning properly, not turning the fan fast enough. Having a blade in front of the truck, or just driving slow as in snow plowing would require the fan to pull the air through the radiator for proper cooling.

Jan 1, 2014 | 08:38 PM

rcnease

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The radiator was just repaired for a small leak and has been properly flushed. The leak was noticed when I flushed the system. I pulled the radiator out and took it to a very reputable radiator repair shop here in town. I also filled with distilled water as we are supposed to instead of tap water. It could be a thermostat, or the hoses. But I don't think there is any blockage in the system. I could be wrong, but I would be very surprised if a blockage was found.

Jan 1, 2014 | 08:53 PM

88LX5.0H

Tuned

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Put a new cap on it. That's the cheapest place to start. Also, jack the front of the truck up while filling it up and let it run for a while. From what I've seen, temp gauge fluctuation usually means air in the system and getting the front of the truck up high (making radiator opening highest point) will aid in getting all the air out of the system.

Jan 2, 2014 | 12:24 AM

phoneman91

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Joined: Jun 2002

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From: Aurora,Colorado

Quote:

Originally Posted by 88LX5.0H

What he said!

Jan 2, 2014 | 12:26 AM

phoneman91

Cargo Master

Joined: Jun 2002

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From: Aurora,Colorado

Quote:

Originally Posted by 88LX5.0H

What he said! And as stated earlier- check you fan clutch-make sure that it doesn't freely rotate when the engine is turned off. Should have some drag.