I have a 96 3.8 Camaro. I just recently had Dobbs flush out my entire cooling system and they refilled it with G-05 coolant. After they did it my car was operating at about 180 degrees. Just recently my engine has started operating hotter and hotter. Some times it gets up to about 230 degrees before the thermostat opens up and it cools back down to about 200. I replaced the thermostat with a Duralast from Auto Zone, and that hasn't really helped. I don't know if Auto Zone just sells universal thermostats that aren't for one specific car or what. Could a bad radiator cap be to blame? Or should I just install a GM thermostat and see how that does?