I was out with the family heading towards dallas for the weekend and all of sudden 2 miles from my house I heard a backfire and felt the vehicle start shaking . My wife starting freaking out !! Turned out that a coil pack went bad. Dealer had one in stock and we were back on the road in 2 hours! I was pretty surprised how violently it was shaking ! Never felt a bad coil pack do that on any other vehicle I owned. It was almost like the bucking you get on a ford when the MAF sensor goes bad. So if your ever cruising and hear a pop and you think you just blew a tire out LOL it might actually be a bad coil pack .

 

Well, the way an engine runs, the pistons move with a balanced rhythm. So if one spark plug isn't firing, that piston isn't moving down with the same speed/power on the 3rd stroke (when plug fires) as the other pistons, so it throws the engine out of rhythm, or balance. Kinda like an out of balance tire. Glad they took care of it for you!

 

I worked for a tech for many years and I will tech you that this was excessive!

it felt like a flat tire or blow out!