As of late I've had some intermittent water loss from my m103 brabus. In a couple 130 mile runs no water can be seen to be lost while in some others about 3/4 (75%) of a liter has gone missing.
The car hasn't been used for a couple of weeks but last night I put it up on axle stands and removed the engine tray. Immediately apparent was greenish coolant (I assume!) on the a/c compressor. I wiped off the liquid, ran the car for 20 minutes or so but saw nothing. I then removed the belt pulley from the water pump so that I could feel the weep hole but it was dry. However, I understand that sometimes it is the shaft which leaks only when revolving.
I know that a/c causes condensation elsewhere in the system on vehicles but surely the a/c compressor would never get cold enough for this as it's bolted to the engine?! New water pump, or look elsewhere guys (headgasket )???