I was wondering what could be causing to loose coolant on my lml, I don't have any external leaks so it has to be internal, could the Egr cooler be failing even tho truck is deleated? Parts are still in place, is there any kits to delete the coolers ? Or how do I check them? I have to add about 1/2 gal every 3-4 months, or could this be the excuse to get a new one lol..