M111 Oil Separator Replacement
I am posting to let people know of the positive results on changing my oil separator. The oil separator is the black box attached to the top of the motor. It has three hoses that go in/out. It can be clogged with oil and varnish over the years, and therefore may not breath or flow air as well.
My car is a 2000, and the hoses were very brittle. They were hardened to the point of cracking, and immediately cracked when I tried to remove them. Be careful not to let any bit of cracked hose enter the valve cover breather hole!
I ordered the parts from parts dot com, including a new separator. Cleaning the seperate would have taken time, chemicals, and would have produced chemical waste, so I just bought a new one. It's about $29.00 on parts dot com. The hoses are dealer items as well. Since the hoses will break when you take them off (99% chance of breaking), you shouldn't start this job without them.
There are only two bolts that take a #30 Torx, use some blue loctite when you reinstall. The job is easy.
The result was a smoother engine. It was obvious from the start. Idle is better, and there is better response throughout the entire rev range. Once again, the improved engine performance also has translated into improved transmission functioning. Total cost was about $86, including shipping.
Anyone with an M111 should do this. These hoses are beginning to dry-rot anyway, and the oil separator can rob you of performance. There are some posts from people who have used chemicals to try to soak out the gunk inside it, but buying a new one is a sure fire way to get the upper engine breather system back to factory-new specs.
Mercedes-Benz - Engineered like no other car in the world.