I have a 01 Hyundai Elantra, and today my cap for the antifreeze blew off while I was sitting idle. We refilled the antifreeze, and right after that, I drove probably a quarter of a mile and my temperature gauge shot up to an abnormal level. My air conditioner also quit working, I don’t know if this is related. What could be the problem? All the hoses look good.
It could be several things but it sure sounds like a head gasket.
Clearly your engine is overheating. The list of possibilities includes but is not limited to a stuck thermostat, a dead cooling fan (or temp sensor or relay), a clogged radiator, and a worn out water pump. Or even a blown headgasket.
Someone needs to look at this and diagnose it.