Just had to fill up the expansion tank this morning...seems to be about 1 ltr. I drove it about 650km in one day and the next morning had to refill, and last week I drove it about 100km in about 5-6 days and had to do the same.

Its not going to the engine since I checked the oil and its not milky white...or blows white smoke. And it runs good.

But now I cant see any external leaks/pool of blue fluid under the car even straight after turning the ignition off and plonking the bonnet up, except the first time I noticed it at a car park and it seems to pooled directly under the rear of the engine, rob101 can verify that.

I have just recently replaced the aux water pump for the heater core, and have moved/stirred/disturbed the hoses around the aux water pump/solenoid valve assembly.

Any ideas, whats the most common m60 coolant leak? I am getting that lovely sweet syrupy smell every time I run the car and open the window or door, so I am pretty certain the leaks external and must be falling onto something hot and evaporating straight away, hence no coolant pool.