If that's the case wouldn't the temperature gauge be hot after 20-30 minutes? The guys at the dealership said that is the way to get the air out of the system, let the car cool down open the radiator cap and let the air escape they also said that it is a messy process. Are you of the understand that it's tough to get the air out of the 2.4?

My mechanic said that with how well it runs, clean antifreeze, clean oil, the car not running "hot" according to the gauge and good results from the block test it didn't look like a head gasket. In the end he did suspect that because we've done almost everything else (not compression test). The other odd piece of the puzzle that I'm not sure I mentioned is that it appears you can drive it as long as you want as long as you are moving and it won't boil over, if you run it with the ac or the heat on it won't biol over and obviously the temp gauge won't go over half way.

In the end getting the head gasket done isn't the end of the world but I'd hate to do that and still have the same issue....

 

If it's just air in the system, every bubble that burps its way out as you watch it is air coming out on its own. If that is diminishing over time, then that would be your problem. If it's staying constant over time, then it has to be coming from somewhere. If the bubbles are pure steam, then there's an overheating issue somewhere. If the bubbles are not steam or air, what are they? The only other source would be gas escaping from the cylinders after combustion via a head gasket leak. There is a test that can be run on the coolant to look for "products of combustion" which would indicate a head gasket leak. It requires sending a sample of your coolant to a laboratory. Not cheap but much cheaper than replacing the head gasket.

 

Well I feel kind of silly but they said it was the radiator cap.... it was a new 16lb Duralast cap from Autozone, they said it needed to be 17lbs, Rockauto also says 16lbs.

It certainly seems to have solved the problem but I'm not sure that was the issue because they also tore into the thermostat housing to make sure the thermostats weren't installed backwards so maybe when they put everything back together they burped the system?..... not really sure but they say it was the cap.

 

Just be glad it wasn't the head gasket.

 

Absolutely, the one thing worse than paying to have a head gasket replaced is doing it only to find out it was a bad radiator cap.