I just managed to fix my rear view mirror on the xf, and decided to take it around the block to see if it would stay in place, got about 300 metres up the road and the engine sounded like water hitting a fan, lack of power just funny sounding. Got it back home and i could smell petrol, lots of it. Dont know why but i took all the spark plugs out 1-5 are white as and no6 is sooty/black.switched the engine on, fired first pop, gave it some stick and blue smoke comes billowing out.Being sunday cant really do anything but tomorrow i was going to call a mechanic and let him have a look see. Is there anything obvious i may have overlooked. The car has been sitting for 3 or 4 days in the rain with a cover on.

Does it sound like it's running on all 6? Alloy head falcons are known to have problems with valves sticking. If it sits for a day or two, it can stick a valve shut, when you fire it up, it bends the pushrod. Easy to fix, but a pain to have to do.
Good luck.

Just took the battery off to reset the computer then decided to take the computer off....full of water....trying to dry it out now....hopefully that,s the problem....

Ok, engine now sounds a lot better but after a minute there was a lot of blue smoke....went to the gym and started it again, took about 2 mins more smoke but lighter in color..more wispish...