so my truck died and then restarted and i was able to drive it home and it would not start again so i changed the starter as well as the battery and it started up perfectly but then after i let it run for about 5 mins gray smoke starting coming out of the exhaust pipe so i shut off the engine and have not been able to start the car up since ive checked spark plugs, fuses the starter and battery are brand new i recently got a new alternator and transmission i cant possibly think of any other causes so if you have any ideas thanks! OH and when i try to turn the key its like it trys to turn over but doesnt quite make it