In Reply to: E34 Coolant Loss posted by Andrew on August 30, 2001 at 15:46:29:
The defective cap causes excessive pressure in the system and leads to failure of a connector on the heater core. All I noticed was a slow loss of coolant and at times would lose enough to cause the low coolant light to come on. I would refill and it would be good for a few days. It did not cause my carpets/floors to get wet. An expensive fix and you need to get deep behind the dash to replace the heater core. Turns out this is a common problem according to my indy shop.
Also saw earlier posts referring to a slow leak on a hose on the back of the engine. Not sure exactly which one. Some of these leaks are not obvious - so may not be the head gasket.
Good luck. Let us know what you discover.