1999 E55 scratch cylinder sleeve
 

I bought a 1999 E55 with 15k miles last month. Ocassionally the engine would run rough when started in the morning, but would smooth out later. My dealer replaced the computer, but the problem continued. Reviewed records and turns out car has had this problem since new (replaced computer 3 times!). My dealer pulled the engine and discoverd scratched cylinder bore (same cylinder that would not fire). MB will repair the engine since it is under warranty, however I am concerned with what would cause this problem in the first place. Should I press for getting a new engine, if possible, or is this no big deal and an easy fix?? I don't want to end up with a mess in 12 months when the warranty expires.

Major Bummer! One doesn’t hear about this type of problem very often on an AMG engine! WOW. I’m not a tech but would suspect that perhaps something wasn’t properly cleaned, or perhaps something chipped off very early on. I don’t know if a scratch in one cylinder will make for a failed engine, but you know that the engine will be pretty well torn down in the process of fixing the problem. You will have a better idea at that point if there are other concerns. I wouldn’t be too concerned as MB tends to do an obnoxiously good job when it comes to repairs. They tend to replace parts rather than recondition anything....

Do you know what the repair shop proposes to do?

You will get a NEW engine short block(or block fitted with new pistons) as this type of failure isn't really repairable.
This happens due to assembly problems OR lack of oil changes, since the problem was there at 15K miles, I would think that the problem was an assembly problem!