Smaller gasket for air chamber on top of valve cover C280 M112 engine
 

I am in the middle of changing valve cover gaskets on my 2000 C280, M112 engine. On the valve covers there is a smaller gasket to the air chambers that look pretty worn and it may actually just be a bead of sealant I have not taken this apart because I don't have the replacement part. What are these gaskets called? I don't see them mentioned in any of the online parts catalogs.

The dealer sent me a picture of the parts in this area and there doesn't appear to be any gasket called for. I guess then that just some sort of sealant is called for?

Hi, Glenmore.

The breather cover (one atop each head/valve cover) is MB's answer to PCV valves. It does not use a gasket. MB has a specific sealant that is recommended, though others have used some of the premium sealants to one degree of success or another.

I can't publicly mention other vendors here at PP, but there is one that sells the genuine MB stuff for under $20 in a syringe, which is an excellent thing, since that allows you to more easily apply the stuff to fill the groove properly in the breather cover before you reinstall it. You have to work kind of quickly and there is a lot of area to cover (particularly on bank 2) so every advantage is a good thing.

You can find some DIYs over at BenzWorld, Kobus has a good one in either the R170 or W210 forum. They are for the M112 3.2L engine, but it's the same exact parts/procedure.

The hardest part of the job is being sure you clean ALL of the old sealant off, as well as oil, etc. You want a shiny clean surface so the new sealant will adhere properly.

Another tip: When you tighten those small screws, use a screwdriver-type torx. Barely more than snug/firm or you snap those screws. The larger ones that go through the breather cover into the head (and help hold on the head cover, I think those are only on the driver's side, bank 2) are 8nm if I'm not mistaken, but that is still not very tight. ;)

Good luck.

Thank you for the info!