If my antifreeze checks out good, why does the temp gauge go lower as I drive?

The car's thermostat will open and close to maintain the proper temperature of the engine. There will be a slight movement of the temp gauge when this happens. The movement should barely be noticeable if you watch the gauge close.

If there is a big swing, then the thermostat is starting to break. It is not an expensiverepair to have it replaced. Also if your anti-freeze is over 2 years old, you should also replace it. The coolant will lose it additives over time and this will lead to corrosion of the system and some expensive repairs later on.

Good luck.

Whats happening is that the natural cooling of the fan in your car bringing in the fresh air is cooling off the engine... Now, this is actually a normal thing and a natural thing that happens... Nothing wrong with the coolant system... It's just cooling off due to the cool air...

My car does the same thing, especially if I am going really fast down the high way, the speed of the air cools the engine, and it's not unusual during the summer time for the car to be fine down the highway and then almost overheat once I've pulled into a neighborhood and almost about to stop...

Its not gonna freeze at five balls, its that as you drive the coolant flows through system faster and will cool slightly, do you have good heat? If so nothing to worry about if you heater isnt keeping you warm then maby you got leak and air traped in system somwhere. Thats a problem , when car is cool before starting remove radiator cover and inspect, check every minmiut or so as car runs and warms up fluid should be visible whole time if it drops and then recovers you low and sometimes this is only clue.

When your car heats up the thermostat opens to circulate the liquid to cool the engine.The needle will move when the thermostat opens because the engine is being cooled by the liquid circulating. if the temperature does not reach normal and is always low you may want to go with a higher temperature thermostat, this will allow your motor to get a little hotter before it opens. If your heater is blowing hot and your cars not over heating you should be fine.

I think the cold air going through the radiator may have cooled it off. Years ago we use to put a piece of cardboard partially in front of the radiator.but this can lead to overheating if too much is covered so you will want to watch the gage. A thermostat that does not completely close could also let water circulate that then would be coole

Nothing to do with the coolant strength. Could be that the thermostat in the engine is stuck open. May need replacing.

actually if your antifreeze didnt work and it froze then the needle would go up cuz the coolant wouldnt be able to flow and cool the engine anymore. you have some other problem. yeah i agree with everyone else it's probably the thermostate.

Thermostat prolly stuck open. When you go faster, the pump runs more cold antifreeze thru the motor than you need.

maby u need to change the thermostat if your car has ran hot then u should always change the thermostat do not ever use the fail safe ones thought u can get if from auto zone for about 5 dollars

Always use a good grade of antifreeze and always change it every year before winter because antifreeze does get weak