My 1990 535iM just burst a leak from somewhere on the passenger-side firewall (visible from engine compartment, not from inside passenger compartment). It happened when I started my car this morning and I got a "coolant level low" warning. I added coolant (but the level seemed fine, it only took a pint before reaching the max--air bubbles in the system?). I turned the car back on and switched on the heat full blast to try and bleed the bubbles out, then something started making a horrible whining noise (almost like belt whine, but not from waterpump). That's when I shut down the car and noticed the coolant on the ground, streaming from the firewall underneath the car's computer housing, behind the exhaust manifold. Any ideas on what just happened? Was that my heeter core dying? The leak seemed to stop (slow?) once I turned off the car, but I'm afraid to drive it like this. Please help!
90 535iM, CCA, sharked