so i have a slow coolant leak coming from somewere ill fill teh resevior and within a week its low again down to the b***om of the resevior. ive looked everywhere under the hood and under put cardboard under the car after filling it up so i would see it and i saw no drips or anything. it doesnt look like there is coolant in the oil and the exhaust dosent smell like it burnign coolant. anyone have this happening or know what it is. also last time i had the oil changed they said there was alot of sludge in my filter even though i run full synthetic and have oil changed regularly.