Overheating after about thirty minutes of driving.
my car started overheating the other day so i checked for leaks and didn't see any. I let it cool down then drove it to a nearby friends and it overheated again so i shut it off and coasted to where i could pull over. This time steam was coming from a broken expansion tank cap. I got it towed home and replaced that and bled it then test drove it. everything was fine but after about thirty minutes it started to heat up again. I let it cool down then drove it home with no problems. When i got home i let it cool down over night then bled it again and more air came out so i thought i found the problem and tested it again and again after about thirty minutes it over heated. I let it cool down and drove it home and let it cool over night and bled it again but this time there was no air. I can see the thermostat opening with my temp needle and i don't see any leaks anywhere and its still full of coolant. I'm wondering if any of you guys think this could be a blown head gasket or, of not that, what you think it is.
Stupid f**king plastic parts!