I suspect that the gauge is fine but the radiator really is overheating.
Sometimes the gauge might drop because the radiator water evaporates to steam or vapor, and that doesn't effectively transfer heat to the sending unit (which is supposed to sense heat). In other words, a puff of vapor or steam blows past the sensor making a false reading.
Don't drive an overheating car (extreme heat can cause expensive problems).
The most likely cause of overheating is the thermostat. Other causes could be a clogged radiator or collapsing lower radiator hose (that lost it's inner spring).
Could be many things, let your moms bf tell you since he is a mechanic and saw the car running.
When situation like this happens make sure you open all the windows first. Instead of putting on the A/C put on the heater! Make sure you got a gallon of water in the car just incase. Keep looking at your coolant level often.
If the car is okey by not using coolant or the motor being normal. It's time to replace the thermostat. Cheers
had the same problem so I replaced the thermostat and the water pump. hope I helped
You should have turned on your heater to high to cool it. You should do that anyway to see if you have any heat. It is possible that the thermostat is stuck shut and is actually very hot there as nothing else would be hot. Except the heater maybe. 180 is not overheating temperature and the gauges can't be running into each other. Realistically. This may be a rare case where an indicator light might be better than a gauge. You are wise to be careful about this. Keep asking here and there til you get a sure response.
IDK, you would need to stop at the garage and have them hit the thermostat housing with a laser temp gun to see what's going on. It could be a bad engine head temp sensor. If that guy pulled the cap off after you drove the car and it was cool, I would lean to the bad gauge temp switch.
First off, it's the opposite of what you did. You should've turned the HEAT on instead of the A/C. The A/C makes the engine work harder.
Secondly, you need to give more info. Year, make and model of car helps a lot.
Thirdly, it's an air bubble in the system or you need a new thermostat.
Sometimes it goes up a bit, sometimes it's down (the gauge)
Today I started it and drove 2 minutes and it was almost all the way at the top so I panicked and turned on my air conditioner (idk a lot about cars I was told it cools down the engine) then it went up to the too completely so I turned it off and pulled over in a convenient store parking lot. My moms boyfriend came (who was a mechanic) and said there was no pressure in the rad and put his finger in there and said it was cold, turned on my car and the fan was running, said nothing was hot and doesn't have any reason to think it's over heating. When we turned it on again the gauge went all the way over (like 180degrees) to the point where it was blocking my gauge thing for my rpm's. Do you think my cars over heating, is it the temp sensor or is it my gauge? Will I have to replace my cluster?
