While turning a corner in my '93 Miata, there was an ominoius POPP followed by a loud THWACKA THWACKA THWACKA. The problem was one of the plus had blown out with explosive force, I put in a new plug and everything is fiune. The three other plugs were snug and subseqiuent checks don't show any new loosening. I'd be interested in theories. My own is thart since the car is stored in bitter cold winter weather
--- 35 below --- the cycle of deep freeze and thaw caused expansion and contraction that loosened the plug and that when I started driving in the spring, it was only a matter iof time before it came right out. Would be interested if anyone has had a similar experience. ds