Water pump gone (m103)?
 

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 :behead:)???

i have seen a lot of water pumps on 103 engine leak from the o ring between the pump and the block at back of pump.it usually does this as engine cools down but if you put pressure tester on warm engine and leave to sit you will start to see coolant going down to compressor.

Also the green coolant has a lot to do with longevity as it is incorrect for this engine and will accelerate corrosion. After repairing the H2O pump, be sure to flush with citric acid and use the correct MBZ or Zerex G05 coolant.