Water temp gauge on panel

[iajet]

My 99 Explorer EB was leaking a small amount of engine coolant so I took it into the shop the other day. Prior to the work performed the temp gauge just barely touched the bottom round portion of the thermometer on the gauge ( roughly halfway between full cold and full hot) and the gauge, once the engine was off and cooled would indicate full cold.

After the water pump, serpentine belt, t stat (stant 13648 180 degree t stat) and t stat housing o ring was replaced the temp gauge never goes above 1/4 up the arc (about halfway to the bulb on the thermometer) and when the engine is off and cooled stays in that same position. However when I start the truck the gauge goes to full cold and slowly warms up never to exceed the position described above.

So my questions are:

1. why does the indicator on the gauge stop 1/4 the way up the arc position and not what it used to (barely touching the bulb on the thermometer/half way)?

2. why does the gauge not return to full cold after the truck has cooled? (like it used to)

3. why does this 180 degree stant t stat only get to 160 degrees as verified with a laser temp gun?

What is going on here?

Thanks so much for your help

 

[iajet]

Well I forgot to attach the picture and now I can't figure out how to attach it.
doh!

 

[iajet]

Well maybe I am not allowed to post a picture....so after the work was performed the gauge is about halfway to the thermometer bulb.

Thanks



click on link below for pic

http://www.explorerforum.com/forums/image.php?u=160289&dateline=1388810708&type=profile

 

[iajet]

One more question if I may...

How would running the t stat at 160 vs 180 - 200 (or whatever it should be) affect the engine, its performance and any other related systems/components, etc?

 

[arco777]

Changing thermostat from the factory rated one isn't a good idea. The PCM expects a certain temperature stat; cooling system properties can affect fuel strategies and open and closed loop operating modes. I would suggest only installing a stat rated at the factory temperature.

Performance is not what you should install a different stat for. While some budget speed freaks may claim power gains "the engine runs better hot", real gains are going to be negligible if any. Most of the time the only effect is confusing the PCM and throwing off the fuel strategies.

 

[iajet]

Turns out it was a 180* stat vs the 195* that i was accustumed to. It now has the 195* stat and all is good.

Tha ks for all of the replies.