I was driving around today, and I notice my temp gauge moving around more than usual. At idle, the gauge would move up all the way to H, and when accelerating, it would move back down. I pulled over to the side of the road, and checked around. Motor didn't feel like it was too hot, and I didn't see any coolant leaks. Fans were on, but after idling for awhile they turned off which means everything is OK? Also, I turned on the heater all the way and cold air came out, which could mean I have no coolant in the system? Broken thermostat or ECT sensor? BTW I'm still running the stock radiator.

 

run the car for a bit until the engine gets up to temperature and then grab your upper radiator hose to see if it is hot or cold. If it is cold or cool, then your thermostat is malfunctioning.

 

NM I fixed it. I was running low on coolant...had a bunch of air in the system.