I should know the answer to this but unfortunately i dont. Here is the deal. I just replaced my head gasket and head studs cams springs and retainers. I did get some coolant in the engine bay, but this is whats happening. First off let me start by saying i blew the headgasket months back and got a new head under warranty. After i got the car back i did smell coolant but it didnt seem to be burning. There is no white smoke coming from the exhaust and you cant smell the sweet coolant smell. All you smell is gas. The question at hand is about the overflow tank. When the car is running the overflow tank fills up, when the car is off the overflow tank goes down slightly. I remember on my dsms that this was the case. The burning coolant smell is annoying and it seems to only be pronounced when the fan is on. I am going to do a coolant system pressure test this afternoon but I wanted some input on the overflow tank. IS THIS NORMAL haha. I should know but I dont. Any inputs are welcome and appreciated. Thanks in advance
-Anthony

 

How long has it been running for since you installed the new gasket?
What i would do is drain the coolant overflow and than run it hard under boost. Than see if it fills up if it does its the headgasket
Im pushing a little bit about 40lbs of boost so were going to pull the head gasket and install the new ams studs http://www.amsperformance.com/main.php which allow us to torque down more

 

the strange thing is this. you have tha max and mix marks on the overflow bottle. Well I marked the spot that its at when the car is on, and i marked the spot that it sits when the car is off. It never changes. when the car is on the coolant sits in the overflow at the same level and when the car is off it sits at that level.

 

are you burning coolant?

 

You either have a bad radiator cap or the hose to the bottle isn't sealing.

Also, since no coolant is expelled when the engine is hot the cooling system is low.