Hi Scotty, I have 2012 Terrain SLT. About a month ago my engine was running hot, I let it cool and saw coolant was low, I added coolant. A week ago engine was getting hot again, I let it cool and saw it was low again. I have not seen any leaks, no water in oil, not blowing steam from tailpipes, no leaks around hoses or clamps, that I can see without lifting car, no coolant on driveway (I put a cardboard under car). My GMC uses the orange fluid, I couldn’t see we’re it was on the bottle, as I had overfilled it. Engine was running and no leaks. So I let it cool then took the radiator cap off and started the engine. I could see it was overfilled, fluid came to the neck of the bottle but did not spill over, but now I can see it leaking! It is leaking from behind the bottle, I can see fluid dripping all around the bottom of the bottle, a steady drip,drip,drip. So I turned off the engine and sucked out coolant and I could see the coolant level on the bottle, my bottle is clear plastic with a black on the top half(my level was up in the black half way overfilled). After removing fluid to the correct fill line I put the cap back on and started the engine. Let it run to temperature and NO LEAKS, I took the cap off to see if it would leak, NO LEAKING. Question is why would it leak when over filled but not at normal fill. If under pressure wouldn’t still make noise? I even poured soapy water all around the bottle to see if it would bubble, nothing. Thank you.