Thermostat issue and or gauge indication problem...help

[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 indicates about a 1/4 up the arc, so about half what it indicated before 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 1/4 indication on the arc.

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?


How can I post a picture?
Thanks so much for your help

 

[iajet]

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



click on link for picture of gauge position after work performed

 

[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?

 

[my98nnj]

Gauge position looks normal to me and I believe the behavior your now seeing is normal as well. Is the leak fixed and do you have good heat? If so, then consider the truck fixed.

 

[iajet]

No indication of any leaks , heat works and pressure check was good. My concern is that the gauge works differently now and indicates a much cooler temp. It is a 180 stat that indicates 160 .

Thanks for your reply.

 

[JimMadsen]

Needle gauges may not be the most accurate. You put in a new tstat that seems to open at a lower temp then the old one. Thus the engine stays cooler since it never really gets up to the temp you saw before. I changed a tstat in my sedan a few weeks ago with a 190 tstat. No reason for that high, just thats what amazon shipped. Even then, my gauge does not go as high as it used to. Maybe your gauge is where it "should" be as opposed to where it was with a failing tstat.

As long as it is all working, let well enough alone. You can drive youself nuts over things like this.

 

[stress301]

Sounds like you put the wrong thermostat in. Mine always stays right in the middle of the guage. The correct engine temperature is critical for engine longevity. It wont effect it short term but you should find the right thermostat for the engine.