Hi,
Iirc, it's one of those. Top one maybe.
Have you looked on you tube? There are videos of it.
I've seen a photo of the pipe leaking to the intercooler and it was covered with white crystals, should be easy to spot if it's a big leak.
How long has it been using 10l a week? Reason I'm Asking is that mine had spells of needing filling up a few times over a short spell then it would calm down.
My tank packed in a few months ago and now mine is turned off, couldn't bring myself to pay the big bill.