Recently my car has been running warmer than usual accompanied by a minor burning smell from the vents, (kinda smelt like plastic not coolant). Using the air conditioning and being stopped for an extended period of time also makes it run warmer, but as soon as I go over 50km/h, it cools down. So, today I was driving home with the air conditioning on, and being on a side street I couldn't drive too fast. The temperature was warmer than usual, and all of a sudden the smell of coolant came through the vents, followed by smoke from under the hood and through the vents. I quickly pulled over, opened the hood and let the smoke clear, then slowly removed the coolant cap with a rag. At this point coolant was pouring from beneath the car and from the coolant reservoir. Did the head gasket fail, or is it something else?
How long has it been since your'e cooling system has been serviced?. New thermostat, New coolant?. Or it could be as easy as a rotten hose that worn out.
there is a tester that replaces your coolant cap with a clear cylinder...... well anyway the glass will turn a color if exhaust gas is present in your coolant..... or you could do a compression test. the reason it was puring out of your resivor is because it was heated liquid tends to expand and relieve pressure the easiest way possible
i hope that helps
i had this happen and it turned out to be a pressure cap. use the exhaust gas tester as stated. should not turn blue i believe
Could be many things...
Check the following:
1)Crank the heat in the car, it should be hotter than usual since the engine is overheating. If its cooler than usual you probably have a thermostat or heater core issue.
2)does the fan kick on when the car gets hot?- could be a probably with the fan itself, or your thermostat
3)check your oil, if it likes chocolate milk you've got coolant in it = head gasket
4)what colour is your exhaust, blueish-white =head gasket
5)take the coolant cap off and let the car run for a while. As the car heats the coolant will overflow, once the fan kicks on the level should drop back down. If it doesn't your coolant isn't flowing properly, probably your thermostat or heater core.
6)is your water pump leaking? = water pump
7)Check all the hoses, its possible they are leaking somewhere
If you do those things you should be able to narrow it down, if you can't then just have a shop diagnose it.
By the way, the reason the car cools down once you go over 50km is because of the extra airflow its not a symptom of whatever is wrong with the car.