It's been rare that I have to tap into the collective genius of the B'Board, but when I do, I know I can count on tons of help and advice... for that I'm thankful.

I suspect my heater core is leaking. From what I can tell, this is supposedly a rare occurrence, as most 7-series cars' heater cores don't go south... it's mostly an issue with the 240s. But here's my symptoms:

- Coolant is leaking somewhere (no visible leakage in the engine bay, or at the heater hose attachments at the firewall)
- I've already done the black light sensitive fluid check in the coolant... none visible in the engine bay or at the drain tube for the heater core/evap system (and this is the wierd part)
- Strong smell of coolant in the cabin, especially when you turn up the heat control.
- Almost constant fogging of the interior windows, especially when you first start up the vehicle.
- Noticable drop in coolant level in the resevior tank over the course of two or so days.

I also had the guys at MVP run a system pressure check, and the pressure did drop, but no leakage was apparent. And with the naked eye, and with the black light, there was no visible leakage inside the car (under the heater core, or around the center console carpet area).

What's also wierd is that there's nothing coming out of the heater core/evap system drain tube (I know, I already said that, but I just had to emphasize it again...)

Any advice? Any help? Consolation? (uh, yeah, I plan to do this job, if the heater core is indeed in need of changing, myself)

Thanks all!
Nick