Bad T-Stat?

[Hunter11]

Does a bad thermostat have anything to do with gas mileage?Mine use to stay right in the middle and now it runs hot for a few minutes and then it will go back to normal. And my gas mileage has gone down at least 2mpg and I was wondering if that had anything to do with it.Thanks!

 

[mike91]

Technically yes - if your T-stat is not funtioning properly and is causing the engine to run hotter. THe cooler the engine the more efficient it becomes and burns fuel more efficiently, hence the need for less fuel. It wouldn't hurt changing the stat since the part only costs a few bucks.

 

[NoBoundaries]

Stats that come on Explorers only last about 3 years or so, I just changed mine at the beginning of this year. I agree with Mike that there is a good possiblity that a bad stat can hurt your gas mileage. Try it out, it is a cheap part and not hard to replace.

 

[JoeC5]

Yeah I got to replace mine also. I am looking at the JET Low T-STAT. Has anyone had experience with the JET Low? And just to make sure, is the a right or wrong way to put in the t-stat?

 

[NoBoundaries]

Believe it or not, there is a right way and a wrong way. Obviously make sure you put it facing the right way, t-stats usually come with instruction on which way. You also want to make sure that the little knotch (Some sort or breathe hole) is facing up. Hope this helps.

 

[FiremanRon]

stuck open will kill gas mileage

I had read something about this somewhere, and combined with a temp gage that barely moved, and some friends who get way better mileage, I changed my thermostat. Temp gage now comes up to the 'N', and mileage went from 16-18 up to 20-22. I cooked the old one on the stove to check it, it was open at 175 vice 195. That fools the computer into thinking the engine isn't warm, so it runs rich. Sort of like running with the choke on. My throttle was sticking shut, too, so when I was changing the thermostat, I looked at that. The whole inside of the intake plenum behind the throttle butterfly is caked with carbon. I suspect that was from the years of running the bad thermostat. The EGR was probably wide open because of the over-rich condition. I should probably change my oxygen sensors now, too.

 

[AgExplorer]

Good point, Ron. Same thing happened to me and the new thermostat increased the fuel mileage about 2 MPG.