2003 we wrangler 2.4l. Engine over heating. Changed out radiator cap and thermostat but no joy. Heater works top hose gets hard with engine on like it has fluid in it. Engine goes above 210 a lil. Then it will all of the sudden spike and peg out. Fluid will be boiling in overflow container. Haven't changed water pump. Not sure if that would be the problem or not. Please help daily driver.
I would try pulling the temp sencor and filling it up to get all the air out of it. If you dont get all the air out it will do that. When i hot air warms up it expands and has no where to go so it boils the coolent and pushes it out the over flow. Start it up take the Rad cap off and crack open the temp sencor and fill until you get no more air. becareful not to burn your self like i did