2003 Elantra 2.0
My engine warms up ok and stays below the 1/2 way mark on the gauge for several miles. Then starts to cheep up and stops at about 3/4 mark of gauge. At this point the ac warms up. As I'm driving, the temp will drop again and them go up, several times. In the driveway, I removed all the covers to see engine. Heated casr up until temp rose, turned car off. After about 10 seconds, a large puff of steam was seen at about mid engine for several seconds then stopped.
I'm waiting for engine to cool then will start removing parts to get down to that area. Any idea what I'm looking for?
Top hose on radiator is hot so I don't think it's a stuck thermo. Is there any kind of relief mechanism on the engine block where the coolant hoses all congregate?