Cold Engine

[Yoda]

I have had this problem for about 8 months now. My cool engine light stays on no matter how long I drive. No CEL or anything related to it. My Scan gauge shows that the max temp it gets while cruising is 118F. If I am stuck in bad traffic and its a standstill, then it will rise to about 140F and the light goes off. When I get some speed it returns to 118F and cool light comes back on.

So my question is what would cause an engine to stay running cool even after an hour of highway driving?

Things I will be replacing are the Coolant temp sensor and the thermostat. That's all i can think of.

[CTScott]

Most likely it is just that the coolant temp sensor is bad.

[bronsin]

wouldn't that mess up the carburation?

[CTScott]

wouldn't that mess up the carburation?

It would make the car run a bit rich, but if you keep driving with it that way the fuel trims will adjust it out.

[Yoda]

I am think so too CT. Easy to replace I will start there first. Maybe that's why its running so rough when its cold out.

[bronsin]

a yup.

[jack black]

Could it be thermostat stuck open? Is heater working OK or too cold?

[Yoda]

Heater is working fine but sometimes when the AC is on cold, it fluctuates between warm and cold.
Getting the temp sensor today to see if that works.

[Bluevitz-rs]

I'm voting bad thermostate.

[Em_]

It's pretty dabgerous because if the fan ever needs to start and it doesnt you can damage your engine

[Yoda]

Have not had the time yet to do it. I will try for this weekend and let you guys know.