2003 F250 V10 - Noticed this morning on the drive in that the engine temp gauge was at the normal mark. I glanced down and noticed what I thought to be the needle moving just a touch, like a 1/4 inch. I of course second guessed my self and had to stare at it for a couple of minutes to be sure it just wan't my eyes bouncing with the expansion cracks in the highway. Sure enough I notice my gauge would be right in the middle where it always sits would ever so slowly rise about 1/4 inch and then just drop back to normal position. When it would drop it was real quick; it would drop as fast as if you were to actually shut the truck off. Now I'm guessing most people would never notice this but I'm just trying to head off any potential problems.

Does this sound like a temps sender, the gauge itself, or may the t-stat?? Keep in mind the temp this morning was about -14*F, I change my antifreeze yearly, the antifreeze is at the correct level, the truck was running for approx 40 minutes, and it did this contiuously. What do you guys think??

I'm trying to head of a problem since I take it hunting every weekend and drive approx 200 miles into the middle of nowhere, the last thing I need is a problem out in the boonies when its -20* outside!

 

JFYI, the truck has 46,000 miles and is maticulously cared for. I'm leaning towards a temp sender since I've never noticed the actual gauge to be very "responsive" and since it's more of an indicator than a gauge.

 

did you check the sending unit? Maybe there is a slightly bad connection? Otherwise I am think the unit too.

 

I think it's normal, and why Ford has dumbed down many of the gauges. People see problems when the gauge moves. Temperatures are not steady, and a real gauge will follow the temp swings. But then people complain.....

When it's -14F outside the radiator is REALLY efficient at lowering the temp of the coolant. When the engine thermostat opens for the first time on a warm up it send coolant at about 200F to the radiator. The lower hose and radiator still have coolant at -14F. That water goes into the engine, which now cools off FAST. The temp gauge will drop when this happens, and the thermostat closes, stopping the flow of hot coolant to the radiator. The coolant now sits still in the radiator, and very quickly goes from 200F to -14F. Then the thermostat opens again, and this happens all over again and again and again....

 

Mark, I fully understand what you're saying. The problem is the ford factory temp gauge isn't really a gauge at all but an indicator that moves at certain temp intervals, which you probably already know. This is why I find this abnormal, since the gauge has NEVER moved from the center of NORMAL no matter how hot or how cold the ambiant air temps has been over the last 5 years I've owned the truck. I mean ford has basically "Dulled" the gauge to the point that there darn near useless. This also isn't the first time it's seen temps of -20*F. It is possible it's done this in the past and I never noticed it but not likely, lol.

I also noticed over the lunch hour that I seem to have developed a whistle, kinda sounds like the whistle of turbo, is speed related, high pitched but not loud, and does it with all the accessories turned off. I doubt this has anything to do with the temp gauge, just something else I noticed.