Check the universal joints and balance of the driveshaft. When you are accelerating pressure is applied to these parts and if they are worn or out of balance or dented they will cause a vibration that will stop when you let off the gas.
It's probably misfiring. You would need to diagnose why.
It was a coil pack.
When bought at a store, I would hope that there was no Pepsi in a Coke (Coca-cola) bottle; I would expect a 2 liter Coke bottle to contain 2000 milliliters of Coke not 2000 milliliters of Pepsi: The capacity of a 2 liter bottle in milliliters is: 1 liter = 1000 milliliters → 2 liters = 2 × 1000 ml = 2000 ml.
2.5 liter V6
From the short description given the first thing I'd check for would be a broken engine mount.
in 2 liter of water are 2000