Worn Coil causing engine knock?
 

My 1995 Mercedes C280 with 140,000 miles is experiencing engine knock under engine load, more so with a cold engine. Sometimes, the knock is bad enough that it shuts off a cylinder, and I must restart the car to restore full power. I also notice some hesitation under full throttle acceleration, many times shutting off the cylinder(s). Awhile back, it was determined by the MB dealer that I did have one weak cylinder coil and it would need to be replaced. I am only using 91 Octane and almost always Chevron gas. Must it be the coil? Plug wires are fairly new too.

THanks.

Problem Deteriorating...
 

I think I'm going to go ahead and buy the new coil and a new fuel filter.