Cold weather question

[flyin-lowe]

Being new to Rangers, and not owning a 20 plus year old vehicle for a long time, I have what might be a dumb question. My son was driving us tonight to meet some friends. Temps outside were fairly cold, around 30 degrees, not too bad. We were on a state road running about 55 mph for a 1/2 hour and the temp gauge was right where it always is, just below halfway. We go on the interstate where he increased to 70-75 mph and shortly after we got up to speed I looked over and the temp gauge was almost down to "cold" similar to when it is first started. I know that there is obviously a good wind chill going into the radiator, but is it common for the temp gauge to drop that much going 70 mph? We drove about 20 miles on the interstate and as soon as we got off and back to the state road (55 mph) the temp almost immediately rose back to normal. Curious if there is anything I should check or would this be normal, it's an 04 with a 3.0.

 

[bobbywalter]

i would suspect that the t stat might be cheating a bit.


i would have to put an actual known calibration gauge to even think about having a concern.

 

[pjtoledo]

my 2000 always held the heat even way below zero. I would suspect the thermostat is not working properly.
is there still good heat from the heater?

 

[alwaysFlOoReD]

If you can, block off half the rad when you know you're traveling in very cold weather.

 

[flyin-lowe]

Thanks, heater was still blowing warm air. I remember bc sick in the day guys blocking the radiator but I never really considered 30 degrees to be cold enough for that.

 

[SenorNoob]

I'm with Bobby. Sounds like the thermostat might not be closing completely, but the factory gauge isn't the most accurate thing in the world either. Watch how much it changes with voltage. Mine drops a about a letter once the battery gets charged and the alternator calms down a little. As long as the heat works and it never goes too high I wouldn't worry about it.