5soko

Hey guys, never saw this actually posted anywhere on the forum so figured id add the document here for reference for current and future members. Thought the more articles we have on here and more knowledge we spread, the better decisions we can all make.
Hence the call for OEM plugs and being very specific when torquing them. Plug has to be a specific length, and when tightened to tq spec, has to be facing the direct injector in the cylinder chamber up 45 degrees either way from it.
Tech service bulletin from Mercedes AMG

Andriy242

I wonder if that was just bad gaping on the users hand.

try m3

Probably the wrong sized plugs there’s plenty of non oem replacement plugs that work perfectly fine.

5soko

Just providing information that the techs at MB have that us customers should have aswell. The better we are all informed, the better decisions we can all make and move this platform forward Knowledge is power!

jvakos

FYI - here’s the PDF from MB about M157 spark plugs indexing requirement since these are direct injection motors and the open side of the electrode needs to be up to max 45 degrees facing the injector (per the doc..not me, just passing along) to avoid possible cylinder damage and converter damage.

Mhoughland

Exactly why I didn’t want to try The colder NGK plugs