Premium manufacturers also have problems
The fact that a premium car has an engine from a well-known brand does not mean that there can be no problems with the power plant.
This was demonstrated on the YouTube channel I Do Cars, which disassembled the Mercedes-Benz M278 4.7-liter twin-turbocharged V8 engine from the ML550 and found serious problems with the cylinders.
When turning on the engine, strange clanging sounds were heard that should not have been there. Additionally, some of the spark plugs had a lot of deposits on them. There was a lot of carbon deposits on the intake valves, even more than is typically found in powerplants with direct injection fuel systems. Additionally, one of the timing chain tensioners was loose.
Disassembly of the Mercedes V8 engine from the ML550 showed deep marks on the cylinder walls.
During disassembly, it became clear that the filter was full of small pieces of metal. Several cylinders have deep scratches. Eric from I Do Cars stated that these scratches are deep enough to not only feel with your fingernail, but also feel with your finger. As you would expect, the piston skirts were also very worn.
Mercedes used the M278 engine in various models, including some E, S, CL, CLS, ML and GL series cars. According to Eric, problems with the engine bores are also present in the AMG version of the engine, which is internally designated M157. The M276 V6 engine is also not immune to this problem.
People on various Mercedes-Benz forums have also reported this problem, but the exact cause is difficult to determine. Some say it takes too long between recommended oil changes. Others claim that the problem is in the piston rings.
