MBS430

I got “Check Engine Oil at Next Refueling” warning at the dash. So checked and found my engine oil level is at LOW level on the dipstick.

Did a little look up and found this TSB:

Mercedes Benz reports that all passenger cars and light trucks equipped with the M272/273 engine (up to June 2998 production) may experience engine oil seepage.
The location could be the round expansion plugs on the rear of the cylinder heads. As of June 2008 production, improved plugs were phased into production.
If these plugs are leaking, remove the existing plugs and replace with P/N A000 998 55 90 (two small expansion plugs) and A000 998 56 90 (one large expansion plug on engines without vacuum pump).

A000 998 55 90 was revised with even newer part number. Ask your part desk and they will tell you the new part number.
good news is the leak was quite simple to fix ... all done within 20 mins and I am a very amateur DIY
I thank this forum and its members in sharing several articles on this subject.

I got all three seals from MB dealer for $16

new seals:



pic of the old seals with missing tabs:





Hopefully this can be an easy DIY fix in case you encounter the same issue

Atcpup

Great Info, thanks for sharing!

Nickthegreek

one question... where did the old tabs go??? I wonder if they are in your chamber