This is in regards to a BMW 4 cyl, turbo, B46 engine from a 2018 430i, 156k miles. Came in running; smoking and running poorly. Broke it down and noted lots of liquid/oily buildup in #4 cylinder. Went through head and replaced cylinder head and unfortunately the cylinder is filling up with oil oil again. Question is could an aluminum engine/block that has been run hot lose the seal at the rings? Prior to removing the head I removed the injectors and spun engine over by hand and it blew a stream of oil out of the cylinder. The head gasket was intact and not damaged when I pulled it off. I've got the crank locked at TDC but can and will roll it over if need be to inspect the cyl walls. I'm starting to look for a good, used, low mileage engine.

Is it feasible that rings could be bad enough that it would fill cylinder up with oil?

__________________
Jim

Yes it is feasible that damaged rings can load up the cylinder with oil. If the perimeter of the piston is wetter and cleaner on the cylinder wall edge is cleaner than the rest of the piston that is piston ring wash. Could also pour kero or diesel into the cylinder to see if leaks past the rings quickly. #4 is probably farthest from the water pump and probably got the hottest and hot earlier.

__________________
"Rudeness is a weak man's imitation of strength" - Eric Hoffer

Thanks, I'll eventually break it down and look at rings on 4.

__________________
Jim

Severe ring wear or piston damage can easily cause a cylinder to fill with oil, especially after overheating. Your symptoms align very well with oil control ring failure or piston/cylinder wall damage. A replacement engine might be the most efficient solution at this point.

__________________
The website jewelerstoolsmall.com supplies the following jewelry making tools: automatic jewelry casting machine, small gold melting furnace, pearl drilling machine

Thanks

I'll find a good replacement engine and drop in it. I had something similar around 1997 where the wife (#1) ran a Mazda MPV hot and did not stop. Did same thing with that one, went through head, put it all back together and that one wouldn't run at all. I actually rebuilt that engine (4 cyl).

__________________
Jim