Car started to over heat today.
 

I was driving back from getting some food and i saw the temp gauge almost in the red so i pulled over and when i pulled into the parking lot the temp gauge dropped back down.. my father thinks the thermostate might be sticking which would cause it to start over heating he thinks when i hit the bump it knocked the thermo loose and it started working normal is this possiable, or could the water pump be going meaning it is working half the time and then it stops working?

it could be the thermo, could be the radiator, radiator cap, water pump ect. have replaced the headgasket yet?

Well the radiator leaks a little bit and i no from where its out the drain plug the radiator cap is also good, waterpump hasnt been replaced no signs of it not working yet and the headgasket hasnt been replaced sence i have had it there arnt any signs of a bhg such as white smoke or milky oil, i replace the coolant like a weak ago i guess i couldnt have put enof coolant in it how many gallons of collant does the stock radiator hold, but i put some more in yesterday and some more in today but it still over heated. And i know it has coolant in it.

Mine does this as well, it's a relatively common problem with the MKIII. When the temperature goes up, turn the air on full blast on 85 degrees. I know it's uncomfortable, but for whatever reason it cools the car down. Also, when you come to a red light, slightly rev the engine. Again, not sure how, but it cools down the engine some. Other than that, take it to a shop.

i have a bhg but no milky oil but theres exhaust gasses in my radiator, if youre topping off your radiator every now and then you should check for a bhg, and about that leak it may be leaking so much that your cooling system is losing enough water to the point where theres not enough to keep cool

revving the engine increases the fan speed so it blows harder therefore more cooling

and is the water in you overflow tank boiling and blowing out steam? and is your coolant a normal color or brown?

Run a block test to rule out a blown head gasket. Then pressure test the cooling system. Your overheating vehicle will fail one of these 2 tests.

If you really think the thermostat is bad, change it. They are cheap and easy to do on a 7M. Then take the one you took out and boil it in a pot of water and see if it opens, then you will know for sure if the thermostat is bad or not.

A stock cooling system holds about 9 quarts. Its 8.6 for an 87 non turbo 5spd