Changed T-stat. Now What????

[npearman]

Looking for a little help. On my 94 EB 4x4 the temp gauge always reads cold, no matter how long I drive it. My heater output is not very good either and my gas mileage is pitiful (13 around town and 15 interstate i.e I have the standard size tires on the truck). I changed the t-stat today thinking it was stuck open and my heater now works better but the temp gauge still doesn't come off of cold. I really need the temp gauge to work because I think it might be effecting my gas mileage because the computer is making the truck run too rich. Do any of you guys think this could be a bad temp sending unit? If so, any idea how hard and how much to replace? Replacing the t-stat wasn't real bad except it was kind of tough to get my hands and tools to the flange bolts. Just wondered if any of you have replaced the sending unit. Thanks

NP

 

[Triton46]

there are two temp sending units right above the thermostat to the right and to the left. Driver side is the EEC temp sending unit (for computer) passenger side is the temp sending unit for the guage. I would suspect the guage is wrong, and that is the cheaper of the two sensors.

Probably best to replace them both. The other thing it could be is the thermostat. I know you just changed it but if it is defective...and some are, then you still have a problem. Did you get a 195? Did you make sure the weep hole was at the 12 o'clock position? All of these things are important. Let me know if you have more questions.

 

[npearman]

Thanks

I did make sure the weep hole was at the 12 o'clock position. I'm not sure if it was a 195 or not. I went to Autozone and gave them the make and model of the truck and installed the one they suggested. I'll probably go ahead and replace the sending units. Thanks for the info.

NP

 

[wrighttl]

I am having the exact same problem. I have replaced both sending units and the thermostat. I checked the actual coolant temperature and it will not get above 150F. I have even tried covering the grill. The damn truck just refuses to warm up.
Have you had any luck fixing this problem.
I have a 94 2wd, 5 speed.

 

[Triton46]

I'm guessing you got the wrong thermostat if you just replaced it and it won't get above 150. You have to use the 195, that is the temp the engine was designed for and none of the sensors (EEC or Temp) will pirk up until it hits this.

 

[npearman]

Temp gage is working now

Originally posted by wrighttl
I am having the exact same problem. I have replaced both sending units and the thermostat. I checked the actual coolant temperature and it will not get above 150F. I have even tried covering the grill. The damn truck just refuses to warm up.
Have you had any luck fixing this problem.
I have a 94 2wd, 5 speed.

wrightt1,

My temp gage is working now. Looks like the new thermostat did the trick. It still doesn't quite get to the normal operating temperature range, but it's a lot closer than it was. The air coming out of the heater is much warmer now and it looks like my gas mileage is going to be better. The only thing I can think of is what the other post said, make sure you put in a 195 t-stat. I'm assuming the one I installed was because the guys at utozone looked it up and gave me the one recommended for the truck. Let me know how it works out.

NP

 

['96explorereddiebauer]

I (my mechanic) changed the t-stat a few weeks ago. At the beginning, the mileage for a tank of gas increased from 240 to almost 270. But now, it's going back to where it used to be, 240, last tank was even ower. I don't know why. Even a long trip doesn't work. I got down to 250 right now and it's close to empty. The temp gauge is showing normal at all times now (when the engine is warmed up). I just don't know why. HELP!!!

 

[npearman]

I just disconnected the battery to see if letting the computer relearn the idle, my driving tendancies, etc. will help with my gas mileage. I'll let you know if this makes any difference in my mpg.

NP

 

[Stephen S]

I've got a similar problem with my temp gauge and heater. My heater takes forever to warm up and when it does, it doesn't get very warm. My temp gauge moves, but it stays pretty close to the cold side. Is my t-stat at fault??

I haven't experienced a low gas mileage like you guys have though. I'm getting about 18 mpg on the highway, so I would guess that's about right.

 

[Triton46]

96,

If your Explorer is warming up now, but the MPG is suffering it may be something else. Mine was the FPR. The mileage this past summer was horrible, changed the FPR and O2, it returned to normal. The MPG dropped again this winter, changed the thermostat and I am at 300 mpg per tank.

Stephen,

Definately change the t-stat since it is the cheapest. I have a 2 door that gets 18mpg in mixed driving. On highway trips I now avg about 20mpg.

 

[Stephen S]

Thanks Triton, just to make sure... I need a 195 degree t-stat right??

 

[glenn233]

Originally posted by Triton46
96,

If your Explorer is warming up now, but the MPG is suffering it may be something else. Mine was the FPR. The mileage this past summer was horrible, changed the FPR and O2, it returned to normal. The MPG dropped again this winter, changed the thermostat and I am at 300 mpg per tank.

Stephen,

Definately change the t-stat since it is the cheapest. I have a 2 door that gets 18mpg in mixed driving. On highway trips I now avg about 20mpg.

That millage sounds great i have a 92 sport with 180K i just changed the thermostsat(motorcraft) put in new plugs and wires and cleaned k+n filter.mass air flow sensor and throttle body,I disconected the neg batery cable for aprox two hours and i still only get 15 mpg on oxygenated(winter) gas any sugestions?

 

[Triton46]

What about your FPR and O2 sensors?

 

[RytM1]

I have run into an MPG problem recently, as well as numerous other members that live in cold climates. Check out this thread, it may give you more things to consider. Dead Link Removed