Rep Power: 0

Just today my thermostat stopped working. It stayed on cold during my one hour drive this morning. I also noticed when I'd come to a stop sign with it in neutral (it's a 5 speed) the engine was idling high for 3-5 seconds before returning to normal. Does it sound like I just have a bad thermostat? I need to drive it an hour to get home from work. Would it hurt if I drive it home?

 
Rep Power: 222

Do you get heat out of the vents? Or does the engine never come up to temp? That way you know if it's a sensor issue or if the thermostat is bad.

 
Rep Power: 224

I hope you've checked your coolant level recently.

 
Rep Power: 511

If anything, better that the thermostat is stuck open than stuck shut. If it never fully heated up, it does sound like a stuck open thermomstat

It's pretty easy to remove and test, and testing only costs you a jug or 2 of coolant and maybe an hour or your time. Replacing it is a cheap and fix, too. You may want to buy a thermostat before testing it if it does show to fail (or replace it anyways because you'll be in there regardless)

Remove the thermostat (drain coolant, remove lower rad hose from thermostat housing, 2 bolts holding thermostat housing on)
Physical check: Check that is actually does move by holding it like a syringe and pressing your thumb on the flat end
Operational check: Toss the thermostat in a pot of water and put it on the stove, see if it opens up when the water heats up. Having a thermometer helps, but not 100% necessary. If you have a thermometer, it should start to open at 168-170F/70-80C and be fully open at 194F/90C, and it should open about 8mm

If it passes the op check, then return the one you bought (or replace it if you're so inclined), fill and bleed your coolant, and keep hunting

 
Rep Power: 367

i think some had issues with aftermarket thermos, get OEM

 
Rep Power: 0

Yes, the heat works fine.

 
Rep Power: 0

The coolant has been checked recently and everything was fine.

 
Rep Power: 0

So, I drove it again and got home fine. A couple hours later I tried to start it and it turns over but will not start. Thinking it's the coolant temperature sensor. Any thoughts?

 
Rep Power: 222

So the gauge doesn't work? Hopefully just needs a new temp sensor. Don't buy aftermarket, only buy an oem sensor

 
Rep Power: 0

(FIXED) Replaced coolant temperature sensor. There are 2 sensors, I just know the one I replaced was not the one where the coolant has to be drained.