Fuck you for making me drive a pink car for six days.
Oil came out looking like, well, oil, so I at least didn’t outright blow a head gasket when it overheated. I still sent the oil out for analysis though, just to be safe.
This is the culprit. There’s a tiny pinprick hole right there where this coolant hose had been hanging against the AC pulley.
The radiator surround has now been overkill fastened to its mount so this should never happen again.