after replacing my heater core. I'm feeling real proud so I pump up the heat even though its already pretty...darn....hot out but I just needed to bask in my glory. I'm cruisin' and decide I've had enough heat and turn it off. I get to the stop light and steam comes rolling out of every open hole from the driver forward (hood, fenders, anything) I pull into the gas station, add some coolant add some water and temp goes a little below normal but eventually goes to where it should be, no worries all the way home. (I did check the heater again when I got about a mile away from my house, no issues) When I get home I took off the plastic plate that goes under the box where the heater core is and I see some coolant. it doesn't make sense to me. Fresh new heater core, hoses were hooked...could it be that because I didn't add coolant right after putting in the new core too much pressure built up from the heat?

 

Everything mass produced has defects. If it does it again and your sure its the heater core its time for an exchange. Just make sure everything is tight like hose clamps and such next time you go for a ride and see what happens.

 

I was afraid of that answer : ( Thanks I will try it.

 

did you turn the heater on full blast when you first adding coolant after finishing the heater core job? Could have experienced china syndrome...