1999 Ford F-150 misfiring

THIS IS SOUNDING LIKE A BLOWN HEADGASKET (WATERJACKET INTO THE COMBUSTION CHAMBER)

THE MISFIRE IS PROBABLY PRE-IGNITION DUE TO THE WATER

SAME THING HAPPENED TO MY '46 WILLYS A FEW YEARS AGO

WHEN I PULLED THE HEAD, YOU COULD SEE WHERE ARCING LEFT MY PISTON WITH A SANDBLASTED LOOK

SAD THING IS, THE PRE-IGNITION SOMEHOW BROKE MY TOP RING ABOUT AN INCH FROM THE GAP, THIS ONE INCH PIECE BROKE THRU THE EDGE OF MY #4 PISTON AND FLOPPED AROUND ON TOP. THIS SOUNDED MUCH LIKE A HYDRAULIC LIFTER NOT GETTING OIL (TAP, TAP, TAP, TAP)

MY JEEP HAS SOLID ADJUSTABLE LIFTERS!

I ONLY FIGGERED OUT THE PROBLEM WHEN I REMOVED THE HEAD

YOU CAN SEE THE OFF-COLOR IN #4 COMBUSTION CHAMBER OF THE HEAD IN MY PIC BELOW- THIS WAS CAUSED BY THE WATER

I'D SAY THE BEST COURSE TO MAYBE TRY IS A COMPRESSION TEST, THEN MAYBE PULL THE HEAD. ADDITIVES DON'T LAST LONG IF YOU TRY TO "CHEAP OUT"

THE MEDIC

NOT SURE OF THE PSI

YOU SHOULD TEST ALL OF THEM, THEY SHOULD BE NO MORE THAN A FEW POUNDS APART. IF NUMBER 2 IS WAY OFF, ITS PROBABLY THE HEAD GASKET

THE MEDIC