wellI have a odd issue that has been bugging the bejesus outta me for a couple months. My temp guage wont heat up over 140 while driving.

Yes I have good HOT heat outta the vents. no my Tsat is not stuck open. while driving for a while my electric fan on the rad DOES come on (still controlle by the factory switch so it is coming on at 230 or so...). If stopped at a light or so on the guage will slowly raise up untill the fans come on and then it drops down just like it should, but once I start driving it slowly goes back down to 140 and stays there. I recently fixxed my Odometer and discovered that my fuel mileage went from 23-25 down to 17-20. Im wondering if the ECU is keeping it in Open loop and adding more fuel....

Runs fine after I get it past the stumble just off idle, buyt I can live with that stumble, I just wanna solve the guage issue.

I just put a NEW sender in the front of the drivers head. guage still goes to 140 and stays. Thinking about maybe replacing the wire, possible break, kink, corrosion ect?? I first noticed this wheni replaced my ECU. but the numbers on my outging ECU matched the ones on the new one, so I dont thinkI got the wrong part. (hope not, that was 2 months ago... Doubt I could return-exchange it now.)

I am planning on getting an Autometer guage as I really dont trust factory guages, but I still need to get this solved if it is giving bad info to the ECU.

thanks to any and all who try to help solve this.

 

so no one knows... great.

 

If you car really isn't staying over 160* or 190*, and it's not just your gagues lying to you, the only possible thing it could be is your Thermostat. Doesn't matter what your radiator fans are doing or what your ECM is telling them to do. Your thermostat cuts the radiator out of the loop until your engine heats up enough to open the thermostat. Hope that makes sense.

 

ok, but I pull the thermostat housing and the T-Stat looks fine, I boil it and it opens at 195ish like it should. Im seriously at a loss here. trying to find an AutoMeter guage that I can put in so that I know it is right.

 

Ok, Installed an Electric Autometer guage. What do you know, while crusing it reads just over 180 on the guage, I have a 190 stat in it if I remember correctly, so that seems good. guess my factory guage just is whackey.

 

You wanna see wacky, you should see my tack go to 6000rpm with a bit of throttle or my speedo bouncing around like an idiot anywhere over 70mph