Several............. It is going someplace, so let's find it, but be ready for an "Easter Egg Hunt". You need to obtain a bottle of UV coolant dye (
UView ) and a UV/Black light. Add the dye and run the car until it warms up. Shut the car down and start looking the engine bay, coolant system lines and hoses, and the radiators over with the UV light in a dim lit shop, any leakage will absolutely jump out at you. If it is an intermix problem, it can show up in the oil or on the plug tips if it is into the combustion chambers.
We do this regularly for customers, parts are cheap and it works like a charm. While looking over the Uview site, check out their “Airlift” coolant filling system, they make the vacuum fill units for Porsche, but only charge about $100 rather than the $750 the dealer gets for the unit with the OEM logo on it………..,