'08 535i - Sputtering & Misfiring, White Smoke, Gas Smell, and High Pitched Noise

[allen993]

2008 535i with 150,000 miles. Daily driverwith 100 mile per day commute. Car had been running perfect when I parked it. Next morning, car started normally, and withinseconds, the following symptoms occurred while car was running:

-sputtering and mis-firing.
-white smoke coming out of driver’s side exhaust only.
-strong smell of gas.
-intermittent high pitched squealing soundcoming from engine bay...as if there is air escaping from something. Didn't trace from where because didn't want to run engine that long.
-CEL…later scanned and found “P0306 - cylinder 6 misfire”.

Iturned car OFF after about 15 seconds. Letcar sit for 2 days, reset P0306 fault code, started it again…exact same thing,except no CEL or any fault codes.

30 days ago...valve cover gasketreplaced, oil filter housing seal/gasket replaced, and a few other oil gaskets/hosesreplaced.
1 year ago...new plugs and coils.

No signs of oil in coolant. No signs of water on oil cap. No signs of leakage around coils (haven't removed to look in coil/plug trough). Ideas ??

[pshovest]

Check belt idler pulleys for squeal.
Misfire might be leaking fuel injector.
Move #6 coil & plug to other cylinders and see if misfire moves.
If #6 still misfires, check compression.
If compression is good, replace fuel injector.