I have an '08 civic si and have been having a coolant issue. Overheated a few weeks ago. Topped everything back off and was checking pretty religiously. Has not overheated since but I have had to fill the reservoir 3-4 times a week. Oil looks brand new (not milkshake like), pressure tested 3 times and never lost pressure, no puddles on the ground anywhere. Strong coolant smell when it gets hot but still unable to find any leaks, puddles, anything. Radiator cap has been replaced. Any help would be greatly appreciated.