Hi guys,

I noticed that my engine is using coolant from the level of the overflow bottle. When I check the reservoir it is full, even a bit past the line where the cap seals. This is when engine is completely cold. When it is hot, coolant level is up to the max in the overflow bottle.
There is no oil in the coolant in the reservoir, and I just replaced the coolant (subaru genuine), the two radiator hoses and a thermostat (for a cooler one - grimmspeed 160degree one).
There is no coolant in the oil (replaced the oil and the oil filter last weekend).
Doug did the CO test and there didnt appear to be any in the coolant.
I cannot find a leak or any traces of coolant anywhere, though I sometimes can smell it after I turn the engine off, and the car doesn't blow smoke.
Does anyone know what it could be?
Next on the cards is a compression test. Where can I get a relatively cheap compression test kit?
Engine is stock and done 150000kms
Thanks for reading.

Adi