Engine Running too cool?

[TheJMan]

I just noticed today that my temperature gauge never seems to reach the "normal" written across the gauge. The only time it seems to work is when it is over 90 degrees outside, and the fan is on, and even then, the gauge just touches the "n" in normal. Is this a thermostat issue, or possibly a bad sending unit?

 

[Jason_25]

Sounds like your thermostat is stuck open.

 

[Stephen]

Yep, modern thermostats are designed so they fail open rather than closed causing the cool rather than the overheat. Running cool is much less harmless, but still robs fuel economy, engine smoothness and causes wear.

Swap out the t stat and it'll go back to normal.

 

[Redrig]

mines that way to i thought that was good and i thought i read somewhere on here that most x's are like that. but i guess i was wrong so this could be harmfull and i should change it?

 

[Stephen]

The thermostat problem is common for Explorers, mine is on its third and needs another one.

Keep in mind that a cold engine causes much more wear than a warm one, but not as much as a hot engine. Thats why everyone says that most engine wear is done in the first ten minutes of driving, when the engine is still cold.

Swap out the t stat and see what happens, its easy to do and relatively cheap.

 

[Redrig]

ok great thanks just to double check when a engine is running normal where should the needle be like maybe halfway ? or doesnt it matter as long as it in the normal range also what a good temp stat to put in

 

[Robb]

Particular trucks will vary where they sit on the range. The gauge isn't very accurate. Fords are very particular in their operating temps and like to be on the hot side.

 

[Stephen]

When new and operating right mine rests about 1/4 of the way in the normal range, but mine is a different gauge than yours.

 

[mcgyver ky]

if

you still want to be sure before you replace the thermostat take it out and put it in a pan of water with a food temp guage and place it on the stove when the temp that the thermostat was designed for is reached if it does not open you know it is bad and not the guage in the truck.

 

['96explorereddiebauer]

Mine is about to go out because it usually sits at the 1/4 mark and my fuel economy is lower than usual (15, 16 mpg instead of 17, 18 mpg). When it was newly replaced, the gauge always sits dead in the middle. When I get out of school for the summer, I'll be tackling that job and do other stuff too since it's hitting 100k mark in about 6000 miles.