Motor only runs when a spark plug is removed

dimebagbubba

2002 ford explorer 4.6 won't start unless a spark plug is removed. Coolant busted out up from behind engine. Started running terrible now it won't run unless a spark plug is removed. Why will it only run while a plug is removed?

cmhj2000

Won't run or won't turn over?

Coolant "BUSTED" out? Hydro locked? Head gasket? Lots of miles???

Mr_Shiftright

Sure sounds like hydro-locking. Does that spark plug have any sign of coolant on it?

I also wonder, if not a head gasket, if the valves are not opening on that cylinder for some reason.