My 2015 C300 4matic is a pre-TSB build (VIN ending 000790, Vance assembly, don't know how M-B's engine manufacturing is distributed). It just crossed 103k miles (~165.000km), but that does not tell the whole story. Originally it was a dealer demo vehicle, so it's first 5k miles were probably entirely abuse. the next 90k miles were done by me in the first 3 and a half years, almost entirely in Michigan, though driving a lot through the midwest, back and forth with the East Coast as well. It was always street parked, regularly getting caked in road salt (I would wash it regularly but still), blanketed in ice and snow, and then of course there are Michigan's infamous roads...



I've had exactly two issues. One was crank position sensor getting dirty causing LOS and irregular misfires. Fixed under extended warranty. Weirdly it never threw a CEL. The master tech at Ann Arbor seemed to suspect that as soon as I went in, so he probably saw it on other M274 engines or other engines with similar configuration. I also had a catastrophic infotainment failure, also replaced under warranty. It was a long lead time part, so that was a little frustrating, but interestingly I found it a bit of a treat to drive my car without audio for a few weeks. I got to appreciate it in more ways. After it finally got fixed, I would make it a point to not listen to any music or allow any phone calls for about half of my journeys every week.
I've really loved my car and I already have many tremendous memories with it as a part of my life and daily experience. I'm looking forward to many more. I'm fortunate to be stable enough that high regular maintenance costs are not a dissuading factor, but I guess I have also been lucky to have had relatively few headaches in terms of having to go to dealers/shops to fix issues. It's been a joy to drive, in the best and worst of whether, on both the most sinuous and straightest of roads, and a joy even just sitting in traffic.

To be totally honest, I've temporarily left Michigan and living situation changed so my car has been re-homed for a while (it's currently best for me to not have my car).
I'm probably going to jinx it by saying this now but I don't seem to have had any of the wrist pin problems (yet). Mine would definitely have been in the batch of engines that were manufactured with the wrist pin machining process having too high a tolerance. I hear the DI noise at idle that is common on pretty much every new engine, but not much else. Maybe I got lucky and the wrist pin in my particularly cylinder 1 is close enough to nominal that it's not a problem? In any case, if I have to get it fixed, I have to get it fixed.
Most likely I'll be moving again come springtime and will (thankfully) have my car back. I'll confirm how it's doing if anyone is still interested.
In the meantime, does anyone have some more complete information about what a loose wrist pin would sound like, or any other symptoms they would exhibit? Aside from the catastrophic failures (gas/oil leaking all over the place, plumes of white smoke) I can't seem to find any consistent information on this. Some say it will be a slapping/tapping sound under load, some say it's when you lift off...all these things can affect the oil pressure and the average load/direction on the wrist so maybe there is no good answer, but any guidance is appreciated.

 

My car is a 2016 C450 AMG upgraded Lorinser Tuned and I'm at 114k km or 70k miles. No problems with the engine, others problems with the car which were all fixed under warranty. Changed brakes at least 3x already but I also drive my car with a Mercedes Enthusiast group during the summer so my car get's used more than normal. Covid-19 has really saved my usage of the car over the last 2 years. Had the Transmission services before it needed to be services because of the driving style, so I take better car of my car than the average person.

 

2016 C63s currently at 127,xxx Miles