maxwerks

Hello ,
I heard that there was a bulletin from Mercedes stating that the spark plugs for the M275 V12 twin turbo engines should be gapped by hand , as opposed to using the plugs pre-gapped as they come in the box , can anyone confirm this , point me to a copy of this bulletin.. did it apply to all suitable plugs ? or only a specific brand ? Thanks a lot .

V12Godspeed

This applied to all plugs I believe, the older Bosch plugs from MB were gapped too wide, they should be gapped to .27, just confirm me on this. They sell a device which you could use and do them yourself. It looks like a half dollar coin with thin edges. sorry for the poor description.

BlownV8

http://images.search.yahoo.com/searc...apping+tool%3B

maxwerks

Thank you guys .. you confirmed my thoughts .. now if I can only find the specs for the recommended gap ... I iwill keep everyone posted .

V12Godspeed

Just call a mercedes dealer and tell them to give you the bulletin. They might do it out of courtesy. I will see if I could post it.

dtohio

The plug gap for my 05,cl65 is on page 409 in the operators manual, .028in.(.7mm), along with tightening tork of 15-22 ft. lbs. I put ngk (rock auto) last summer, they were gaped to within .001, I wouldn't fool with anything that close.

driveability

Sounds like they are trying to blame the 65 coil pack failure on the plug gap.
I worked for G.M. as a tune up tech and the factory blamed us for over torquing
the battery terminals as the battery terminals were beginning to fail. Well it turned out the battery construction at Del co was at fault. LOL