Kind of a stupid question but I'm used to cooling systems where the cap is on the actual radiator. Little back story, replaced gallery gaskets, did a bunch of other stuff while in there like the water pump, flushed radiator, etc. After the gallery gasket job, I tested it and installed a Stillen supercharger kit,. Burped coolant using a no spill funnel and then worked on the base tune. During the first run on of the coolant lines on the TB popped off and was blasting coolant on everything for 40 minutes while I was driving before I noticed. Stillen doesn't give you the correct sized hoses for the coolant lines to the TB's and expects the hose clamp to make the seal. Anyway, I immediately replaced all the lines with the correct ID ones and burped the coolant again. Now the overflow tank level is fine but when i pop the radiator cap off it looks like it's losing an ounce of coolant every time I drive it. Either that or I'm an idiot. This isn't my picture but just to reference, I fill the coolant up to the blue arrow and it drops to the red arrow after driving. Am I an idiot and it's supposed to be at the red line? I'm used to opening the cap directly on the radiator and seeing it full to the top. Also checked oil, not milky.

 

Is your reservoir lv going up . Seems like when you drive it ,its getting to running temps Which is hot and it is expanding. The overflow is probably going into that hole you see and into your reservoir. Once it cools it just drops that ounce your talking about

 

Yea the reservoir fills up no problem. I guess once the coolant contracts it's got a little extra space up there for whatever reason.

 

I recall it should be at the blue line. Is it possible there's still air in the system?