was driveing my 172 yesterday when smoke came from back of car.i pulled over to check. o my god what a major blow this was. the car wont start again.just heard from local dealer that up to now they have found a MELTED spark plug in her and the head is coming off to check what damage is done. the car has only done 20,000 miles. and before people saying it i wasnt blasting her and yes she did have water an oil. not being nasty but as you can problay guess bit pissed off.