Mine is an 08 with a V6 that uses a pressure cap on the tank. Pressure test caused a leak out the vent.

 

Looking on RockAuto it would appear that on the 2.4l the overflow tank is non-pressurized but I can check with my mechanic to see if he tested the rest of the cooling system.

https://www.rockauto.com/en/catalog/...rvoir+cap,2067

I read a bunch on this forum and this is almost exactly what I'm dealing with but this guy has a 2.7l V6.

boiling antifreeze reservior - Chrysler Forum - Chrysler Enthusiast Forums

 

Well it's not the water pump.....

I'm at a loss I guess it's time for the dealership.

 

My mechanic is great even though he didn't get it figured out, he charged me less than $350 to install the water pump, radiator, thermostat housing, go back and install new thermostats, pressure test the cooling system, do a block test multiple times, trouble shoot the car and even take it to his mechanics friends to get their ideas. He has his own shop and I've been using him for the past 15 years this is the first time I've seen him stumped, the guy even lets me bring my own parts....

Anyway at this point he thinks it may be the head gasket not because there is antifreeze in the oil or oil in the antifreeze, not because it runs bad, not because it overheats (by the temperature gauge) as a matter of fact it runs fine and cool enough at constant speed but because he has exhausted all other options. The car is currently at the dealership they will look at it tomorrow.... I started calling around and I've gotten one price of $1500-1750 for a head gasket.

I'll keep you guys updated (it drives me crazy to get 20 posts in to a thread and not get a resolution).

 

Did you run a pressure test? The most fundamental rule in auto repair is always rule out the cheap things first. Going to a head gasket without ruling out everything cheaper is not wise. Make sure they do a compression test and check the coolant for products of combustion before pulling that head off.

 

The mechanic did a pressure test on the cap and the rest of the cooling system and he said it checked out, he also said that he did a block test a few times to check for gases(?). I did ask him about the compression test and he did not do it if I remember right he put a lot more stock in the block test but I think your right I may ask the dealership to do that.

He did tell me that the block test isn't a 100%. If the block test is good and the compression is good is that a "sure" way to rule out the head gasket?

 

I just came back from the dealership because they couldn't replicate the problem they thought it was simply air trapped in the cooling system that had cleared itself, I stood there with them for 5 minutes and I started seeing a bubble then two then it got worse they said it's air still trapped and needed to be burped but he also said that it was probably a thermostat installed backwards. (I hope it is)

 

Trapped air should work its own way out after a few warm-up and cool-down cycles of the engine. You will probably need to top off the coolant to fill up the space occupied by the air. Trapped air should make itself known as soon as the engine warms up.

Likewise, a thermostat installed backwards will result in overheating pretty quickly. The temp gauge is likely to just keep rising as the car warms up right past where it's supposed to be to the overheating side of the gauge.

I don't think you reported those symptoms above so I doubt that they have found your problem yet.

Did your mechanic install new radiator hoses when he replaced the radiator? Hoses can suffer a tear in their inner lining which can operate like a flap in the hose and obstruct flow.

 

your guy can get a funnel that will sit on top of the radiator cap. Fill it to have some coolant in there let it run and watch bubbles come out. If the bubbles still come out after 5 min of running and the fluid level does not drop when more bubbles come out you have a warped head.

 

The dealership said that getting trapped air out is tough in the 2.4l if you aren't familiar with it, I don't think that I've read that before?

It takes the car about 30 minutes to start bubbling over and it doesn't "overheat" according to the gauge.

No he didn't install new radiator hoses, he did install the hoses going to the heater core. I don't think that's the issue but you may be right I have a feeling we are chasing an oddball issue that doesn't manifest itself in the normal fashion, my mechanic did mention that the bottom radiator hose felt too cool. Wouldn't the temp gauge read hot?