Stuck Thermostat?

[BlueRidgeHunter]

My 2004 XLT 4.0 is running cool. The temp gauge only goes to the 1/4 mark even after an hour on the road and the heat is cool. Should I start with replacing the thermostat?

 

[Number4]

Driving, rather unimpeded (light to no traffic) these engines maintain a steady temp of 196ish degrees (basically, running with the stat open.) With traffic, you'll spike to 206/8° during the winter. (My experience.)

If you are blowing cool air, I'd suspect you are low on antifreeze, but that doesn't jive with the temp gauge. Your gauge, whether at 194° or 220° Should be at or just below the middle.

The first tic mark on the gauge is 170°+/- from my notes. It doesn't even start moving until around 135°. At 170°, you should be feeling warm air.

Does your overflow bottle ever fill up?

 

[BlueRidgeHunter]

Coolant tank is full. It has warm air blowing buts it not warm enough to heat the cabin to a comfortable temp. Could it have a 170 thermostat in it?

 

[mountaineer2004]

I had a similar problem with my Grand Marquis...replaced the thermo and all was warm again. I'd start there.

 

[360cid]

I just replaced my thermostat about a month ago for the same reason. Only would come up to the one quarter mark on the factory temp gauge and did not blow vey warm out of any vents. It is super easy to change 'em though! Probably the easiest one I have ever changed. Took all of 10 minutes, including topping up the coolant! Temp gauge back up to almost half-way point and nice and toasty in the cab!!

 

[BlueRidgeHunter]

I just burped the system and it improved. It's running much warmer.

Should i do it again just to make sure the air is out?