After driving 20 + miles and then turning off and restarting the next morning I get a knocking noise coming from the engine. Not a ping a actual KNOCK!
I have took it into Service and they can't find it but it is there. Please help me with this :roll:

If present with a cold start then goes away in a couple of seconds, the most likely culprit could be your timing chain tensioner bleeding pressure overnight.

Timing chain tension is maintained by oil pressure acting against the tensioner piston. It should not lose pressure (has a non-return valve) over the short haul. If it does, the knock may be chain slap until the tensioner mans up. Not likely in such a new car unless there is a failure of some sort, like the pressure retaining non-return valve.

Not a good condition to keep driving. A failure in that chain arrangement usually results in a total engine rebuild since our engines are interference-type.

If the knock is always there, forget everything I said.

If I understand your post, the knock is loud and steady with engine speed. I would have this car towed to the dealer repair shop before driving further.

I assume you have checked oil level in the engine. Is the sound only at cold start, then goes away? Is it present at all times? Regardless, it will not go away by itself. Our Mercedes engines should not make loud mechanical noises. You may have to leave the car overnight at the dealer or repair shop for them to hear the noise at startup.

To answer your specific question, if you have driven it 20 miles in that condition then you probably have not made it worse but I would drive it no further until repaired. You may be on the edge of a catastrophic failure.