1993, F150 V-8... Recently I had the small L shaped hose crack and I lost about a galloon of anti-freeze. I did not over heat however after the mech's changed the hose and added back the anti freeze.....my water temp gauge has been in a steady state of motion. I do mean steady motion, while I'm driving the guage roams from just shy of cold to just shy of hot. Water level is normal, oil level is normal and it is not overheating..... Is this simply a sensor issue????? Please advise.....

 

Sounds to me like you might have an air pocket. Try running it in your driveway with the radiator cap loose for half hour or so after it warms up. It should burp it out.

 

This is becoming another case of experimenting by the mech's.... I had the water temp sensor replaced, mech's said check indicated it was out of range/bad. Shoot a temps around the block and discoved the thermastat might not be operating as designed. Changed that. So $120.00 dollars later....I have somewhat corrected the roaming temp hand BUT I still have issues. My problem seems to be in the area of circulation. Water temp seems to stay in the center of the normal range at idle HOWEVER, when I accelerate the temperature goes up to the high end of normal. With the radiator cap off, you can observe what seems to be a lack of circulation. Thoughts>>>> Maybe a partialradiator blockage, BUt the mech's are leaning towards a water pump problem. My issue....is this simply another case of guessing which means more money out of my pocket and still the same issue. PLEASE advice!

 

Remember
The stock gauge is a glorified idiot light. Before you spend a ton of money put a manual gauge on it. You might want to have the cooling system power flushed also. My 92 had 96000 on it when i bought it and was pretty cruddy.

 

The mechs may have put a hotter thermo in than you had before.
Ask them if you should expect the temp you are getting. Most my vehicles run lower idle temp than driving. I have watched the radiator and it seems like a very long time after you start it cold before flow begins. Even then the flow don't last long and it seems like a long time before it starts again. And the level drops when the flow starts. I spend too much time looking down holes.
Radiator Gazer

 

I had this same problem with my truck, I replaced the thermostat first and found it would run at a low/normal temp when idling, when on the freeway it would jump to the top of the normal range, in the too hot area. I replaced the water pump and that fixed that problem, now I just cant figure out why it wont heat up past about 150 deg, the low point on the normal range.

But the water pump replacement did fix the jumpy temp issue.

Good luck.