driving my 2011 transit xlt at about 60 mph suddenly engine starts misfiring check engine lite on the whole truck shackeing like mad speed and revs dropping like a stone i pull over and check all the obvious things all seems normal except the unholy shakeing ang roughness, i limp my truck home get it towed next morn to ford they tell me the windshield washer jets leaked washer fluid for an unknown amount of time into a spark plug well and eventualy caused the plug and wire to fail. Thats when you realize just how much you need all four of those cylinders firing to pull that little tiny turkish mule down the road.. well in the end ford fixed it all , new washer jet seals new plug and wire, they paid for the tow. But what a silly thing to ground my truck, it felt like the engine was done. so beware if you feel the shake. I do applaude ford for taking great care of me. be well.