blue-white smoke from exhaust and gasoline smell

[erictown]

OK, here's what i did this morning on my wife's Matrix XR 2007. 38k mile.

Changed motor oil and filter, 4.2 L 5W-20 (i know it should be 5W-30, but..) into 1.8L engine.

I took out one spark plug for checking, it looks fine. I put it back and connected it as original.

I started the car, HOlly! engine set shaking like mad, large amount of blue-white smoke out from exhaust with strong smell of gasoline.

I check and re-fix all connection of spark plugs, they look fine.

Restart the car, viberation gone, blue-white smoke lasted about 5 minutes, and diminished,

I was trying to put the plastic engine shield back, this phenomenon happened again once. I recheck all spark plug connections again and carefully put shield back. no more wackies.

Now, I am very curious about this, it seems like a misfire, but can a single misfire bring that much blue-white smoke out exhaust? if not, what could be the possible reason?


PS, I checked PCV valve as well, seems nothing wrong.

 

[fidom]

I wonder if the oil filler is badly positioned and allows you to pour oil directly onto a valve? If the valve happened to be open, some oil might seep past the guide and into the cylinder. Using such a thin oil would make such an occurrence more likely but I suppose in Canada you need special oil for the cold winters? If there was much oil you could get hydraulicing, which can damage the engine.