Hey guys my car does fine at idle and in traffic but once i get up to speed and cruise it wants to hover about 1/8th above the C on the gauge. but when in traffic or not moving it is in the middle. Bad thermostat or coolant temperature sensor? Which one is more likely?

 

You mean it cools down at high speeds?? If so, it's normal because there is more air going through the radiator at fast speeds so it's colder air, therefore cooling the engine more. What temp exactly is it dropping to?

 

I disagree. Unless you are coming down a mountain with the throttle closed the temperature should read the same all of the time once warm.

Which is more likely to have failed? Dunno, but the thermostat is easy to change.

 

I agree, once my car is fully warmed up, it never dips under where it is. (Just under half way ) even during really cold nights, light throttle. And also never goes up, constant boosting & hot days...

 

Doesn't sound normal, mine stays at just below half way once I'm up to temp, no matter how cold the weather gets.

Do you have a water temp gauge? Should see what it reads.

 

It gets pretty cold. About 1/8 from the C on the gauge but if I stop it goes right back to middle. Sounds like a thermostat or coolant temp sensor for sure but idk which one is more likely. I guess I'll buy one then see and if not buy the other haha.

 

My bad thought you were refferring at the center gauge cluster pack.

 

Its easy to check the temp sensor, measure resistance on the sensor with a multimeter, I dunno the specs though, look em up. Oh and get a wiring diagram.

 

Prob the thermostat and I would do that first. Its not supposed to get colder as u drive faster....the whole point of a thermostat is to keep a temp around one temp duh. If you set the thermostat in your house to one temp would you want it to cool it down in the winter when you wanted heat?

 

I agree with the other... Thermostat is probably stuck open allowing the coolant to constantly cycle through the radiator.

 

Haha no "duh" is neccessary the coolant temp sensor could act up the same way. I'll change the thermostat first and see how it goes