The hoses weren't capped off ever, the prev. and only driver/owner was a 50-60y.o. nurse in Florida who must have run almost straight tap water in the system. I've never seen such bad mineral deposits, the water pump impeller was almost rusted solid. The outlet "L" on the thermostat housing was corroded almost solid and looking at the TB side it appears to be the same. All aluminum fittings are corroded and pitted.
I discovered this while doing the timing/water pump change this week. The car hadn't been started for the past 6 years, but had been garaged; and supposedly only virginal BMW certified mechanics with white gloves were allowed to touch it.
They just never put antifreeze in it.
I plan on doing a complete system flush, but I wonder how bad the heater core is corroded as with other things. It's run fine for the past 4-5months since I bought it, I'm amazed.
I still think with getting out all the mineral deposits I should pick up at least 25-30hp
.