Sludge under the valve cover!!!
 

Good time of a day guys and gals. I am asking about you help. I have 06 530Xi SW. Car has 128k miles on it, I am not the first owner.
I went to replace valve gasket cover today, when they open the cover , here is what I found (Picture attached). Do you you think it's a good idea to clean it or leave it as it is?
It's already cause 1 of the valve lifters to got stuck, which caused random missfire and etc.

Wow that is terrible. If the engine looks like that then it makes me wonder how good was the rest of the car taken car of. I would find a way to clean it since it is cause you issues.

The car is not bad at all. What I guess somebody mix mineral and synthetic oil, or something in this ball park.

Do the next several oil changes at 3,000 mile intervals and prior to the oil change put in Liqui Moly engine flush.

Maybe every 1,000 miles for the first 2 changes. Be sure to get some road time in to get the oil up to temp and flowing around good.

I've definitely seen much, much worse. I agree with NoQuarter, I think if you do what he suggests you'll get rid of most if not all of that buildup over time.

Assuming it's not burnt on, I'd wipe off as much as possible to get the top end as clean as I could manually. Then a 1K change followed by a 3K and back to normal.

I'd be sorely tempted to drop the oil pan an inspect it and the oil pump as well.

This engine flush stuff is the real deal, huh? No side effects or anything?