The engine runs fine, nice and smooth UNTIL it is WET., It will buck and hesitate, never stalling completely but enough that a BANG can be felt when the engine hesitates enough to twist the engine on its mounts (it actually broke a mount). This MOSTLY occurs at any speed in any gear, with or without o/d selected, in 2wd or 4wd if it is RAINING, MISTY or SNOWING. It will occur all winter from first snow till last wet if off the road. I have replaced the wires, the plugs, the ignition module, the MAF the EGR, I have searched the internet and every forum I could find. It is hard on the vehicle (note the broken engine mount) and on me since I have no confidence in the truck. I bought the truck in the spring of 07 with 190000 km on it in Winnipeg Canada and it ran fine till the fall (then the rain/mist/snow/cold began) and its been doing it since. Ford can't find a fault and just wants to throw parts at it; my private shop does the same... IF ANYONE KNOWS, REALLY KNOWS WHAT THIS IS PLEASE POST.

There seems to be a problem related to moisture, but we can't pin it down and the local dealer has been of no help. When driving my 99 explorer when the roads are wet or snowy, occasionally the engine will "buck" or hesitate. Frequency varies from every 1 to 10 minutes when cruising. Does not buck when idling. Coincidentally or not, this problem appeared after installation of an intake gasket. No code shows up when problem is happening. Ford dealer also changed plugs and plug wires (currently they seem to be attempting to correct this by the process of elimination) and then took it for a test drive and it was worse than before. Oddly enough upon reviewing problems at 2carpros.com another consumer has this identical problem. Their answer was that thye should double check very closely the wiring around the engine. We let the garage know this suggestion. They have now brought it to a larger dealer in another town. They also consulted the Ford hotline regarding this, which I think is what led them to replacing the plugs/wires. The next step I guess is for them to Ford field engineer to help with diagnosis. However, we have also been informed if this is necessary we will incur the cost of $125/hour. What to do? What to do? If their local dealer and consultation with hot line expert can't solve a problem with their own product, which they manufactured and should know inside out - why should the innocent consumer end up paying thru the nose.