Car started to over heat today.

[Sinistral]

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.

[oowee623]

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?

[IHateHacks]

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