Temp gauge Irratic

[Tsgs69400]

Hello,
I went on a 100 mi round trip today to get some parts and on my way back I glanced down at my temp gauge and saw that it was irratically moving from the cold line to about the "o" in normal.
I pulled off and checked the coolant and it was fine. No bubling or anything.Nothing dripping on the ground. I was getting no white smoke from the exhaust(thinking head gaskets).
I added a little water to bring it to the top of the line "1 qt"
I drove along. The outside temp was only around 75 so it wasn't hot.
As I'm driving I can see the gauge fall and flutter about every minute or two. ( makes sense since it is probably the t-stat opening.
It just seems to me like I am getting air in the system but it has never done this before. I am running Rotella Diesel Coolant which has all the additives in it and is certified for Ford and International.
BTW" my water pump and sensor is only about a year old.

Thanks Guys

[thorx4md]

My coolant gauge is doing the same thing. Gonna put a new sensor in tomorrow to see if that fixes the problem. It will suddenly drop from normal all the way down to cool and stay there. Clutch fan has been running alot also. I also noticed that as soon as the clutch fan kicks in, the A/C cuts off. Must be linked some how.

[tsteel]

I have seen some do this when the thermostat opens. I dont know exactly if anything else can cause this.

[thorx4md]

Wife is bringing a new engine coolant sensor home. Will replace it tonight to see if that fixes the problem. I am hoping it is not the head gaskets causing all of my problems.

[thorx4md]

Put in new temp sensor and new thermostat and that gauge problem is fixed. Now I have the tea kettle whistling noise out of the degas bottle. It is going in for head gaskets, studs, EGR cooler and Oil cooler this weekend. Aslo replacing HPOP connector and various other 0-rings that are known to go bad.