2016 SQ5 - coolant always at min level

When I bought this car about 2 years ago the coolant res was at min level when I test drove it. I also saw codes for the coolant pump which was quickly replaced along with the thermostat and PCV about two months after buying it. Since then I’ve not had any noticeable issues but the coolant res always ends up at minimum level mark regardless of me topping it off. I’ve noticed it takes anywhere from a week or two to about a month for this two occur after topping off. I understand the level will typically increase under temp but I am unclear on how it’s dropping. There are no signs of an external leak anywhere that I can see or smell. Anyone else run into this or have any thoughts as to why the behavior is occurring?

Is the car tuned. If I remember correctly people running more boost were consuming some of the water in the non divorced IC system.

Nope - stock tune. I do have a 034 Motorsports intake tube and 034 bleeder screws on the SC. It occurred to me after I posted that perhaps one or both of those screws aren’t tight enough?. I was also thinking about pressure testing it’s just odd it seems to always eventually drop right to the min level when cool but never any further regardless how much I top off with (usually I fill it smack dab in the middle of the min/max level).

Yes I’d check those and then do a pressure test. That would make the most sense.

Open your oil filler cap and look at the bottom to see if it looks milky. The PCV/oil separator on these 3.0Ts have a tendency to leak coolant into the oil.

Oil cap looks milk free to me. I did just do an oil change about 3 weeks ago. I had sent my previous oil change to blackstone about 6 months prior to that and they did not note any coolant. I gave the SC bleeder screws a tiny fraction of a turn to see if that will help. Do either of you think it is possible I have some type of weird air lock issue?

Fill up collant tank, do hard drive for some time to get things heated up and expand. Go behind of car while engine is running, observe exhaust, if wet stick fingers and inspect what kind of it is and smell. On one car i had cracked head and it was comming from max to min in week. SC cooler is good?

How good is you colland cap? Maybe its leaking and not holding pressure? I replaced my recently because part that hold rubber seal disintegrated.

With your head issue did it ever go below min or did it get to min and then stop? Mine seems to stay right at min and never get lower.