Hi everyone,

I wanted to give you an update on my issue. I took the car to the shop, and it turned out that the head gasket had cracked, causing coolant loss.

I bought a new cylinder head and installed it on my M274.920 4MATIC, but after just 20 km, the engine failed. The crankshaft bearings failed, and the crankshaft spun, leading to a complete breakdown. 😞

So, if you're experiencing issues with the M274 engine, my advice is not to rebuild it—just go for a new or low-mileage used engine instead.

Ouch, that engine is junk now. Spun crank shaft bearings usually fail due to lack of lubrication.

I'm curious, how many miles total on that engine and did you buy it new or used? Also, what type of gas were you using and what was your oil change regiment?

Sorry to read about you loss.

thin oil film with limited oil pump pressure does have its limits...