Okay, my 2008 grand prix is throwing a cylinder 5 misfire. (3800 v6) You can hear it when the car is at an idle but cant figure out for the life of me what is causing it. Changed plugs and wires. Switched coil packs, And that plate they sit on, I cant remember what it's called. Checked the fuel injectors. Did a compression test that's all good. My buddy even had one of those scope cameras and checked around said everything looked good. Replaced the rocker arm for cylinder 5 and it did nothing. I dont have any oil in the coolant, or coolant in the oil. Is there anything else I could check that would cause it? It's only throwing the cylinder 5 code. Its been sitting over the winter and I finally started it yesterday, and it smoked some down by the spark plug I believe its number 5 in the firing order. Could just be from sitting for a while, but at this point I have no clue.