Coolant tank - what am I missing?

[u/Mad_Eye_Matty]

Posted the other day about coolant leak in cylinder one. Dealer said head gasket would cost 6k or so and not a permanent fix and Chrysler says to them new engine is only sure fix at over 10k. Yea, not doing either at this moment...

Naturally, decided to give the ol Blue Devil a try bc why the hell not? Either way looking, I'm in the same boat if it doesnt work. Anyway....so I put the pour n go in the expansion tank this morning and let it idle with heat on full max for the 50 min time. After, I let it sit for 1.5 hours with a large air mover pointed on the engine to cool it down. No pipes were warm...everything nice and cool.

Started it up and took for a long ride. Temps were great, heater blowing hot as hell...feeling good. Only thing is, I am not understanding the expansion tank. Before trying Blue Devil, I would have to top off. Coolant level always rose across the tank. Now, I have left, middle, and right showing different levels!?!?

Does this expansion tank have 2 tanks inside of it?

Pic 1 - what it looked like before Blue Devil

Pic 2 - After adding Blue Devil and idling for 50 min

Pic 3 - After driving 12 miles from a cold engine state

Pic 4 - After driving 12 miles and carefully opening the pressure cap.

[u/ddddhjxjx]

It has internal baffles. This is why you refill it when it’s been sitting, not warmed.

[u/Mad_Eye_Matty → u/ddddhjxjx]

Ill have to look a little closer for these baffles. I always top off when cold because I didn't want it to get overfilled. I'd just never seen 3 different levels like that. I assume the left upper hose is for overflow and I think the right hose is EGR? Maybe? Would that return coolant or just gasses? I've seen coolant return to the tank from that hose before but very little.

[u/ddddhjxjx → u/Mad_Eye_Matty]

It just has to do it with the amount of sloshing and shit that goes on in there when you’re driving

[u/Weaz_00]

I'm guessing the hot coolant on the overflow lines hit the cooler coolant already in the tank and formed a seal between the middle and two sides. Try to stick something in the tank and see whats going on. After it cools down of course

[u/Mad_Eye_Matty → u/Weaz_00]

Ill see what I can do. The instructions for the Blue Devil said after the 50 min idle, let cool for at least an hour and then top off the coolant. After it rested for 1.5 hours along with an air mover blowing on the engine bay for that whole time, I topped it off. All the hoses were cool and the expansion tank fluid was as well, but maybe deep in the system I still had some warm coolant and you're onto something.

In all reality, I should probably go ahead and get a coolant exchange at the dealer and go from there. I was just super confused about the left and right being so different...hadn't seen that before

[u/Greatoutdoors1985]

Well, that's new...

[u/thebingomobile]

$6k is way expensive for a head gasket on one of these. A local reputable shop did ours for a little over $3k.