when i drive my teg on local, temp gauge is normal, but when i hit the hiway w/ speeds of 50+, the gauge goes to cold...anyone can help me??

i am thinking sensor went bad or voltage thing...not sure how i would check..
Help...

 

Someone on G2IC had this problem, I think a new OEM thermostat solved it.

 

The thermostat is stuck open. I bet it takes a LONG time for it to get warmed up too, right? Like 15-20 minutes after you start driving? Replace the thermostat and I'm sure that will fix it right up. I changed mine when I replaced my radiator, and now my car is up to full operating temperature withing 5 minutes of starting to drive, and it stays there rock solid all the time, no matter if the car is moving or stopped, A/C on or not, heat on or not, the coolant temp. guage stays the same all the time.

 

yea, it does take quite a time for it to warm up...but only on hiway driving, i get to cold on the sensor..

 

okay so, replace the thermostat.