no had to modify engine

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1999 w140, quit voting to old, and to old to fight, a god damned veteran, deutschland deutschland uber alles uber alles in der welt

PColumbo, try lightly prying under the problem coil pack with a thin piece of wood protecting the valve cover. After you remove the coil pack I would suspect the grounding stud can be removed and replaced. It may be left-hand thread. Best to have MB-trained techs work on your MB vehicles.

As mentioned, Bosch F8DC4 spark plugs (gapped per the Owner's Manual spec) work best in the M104 engines.

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Fred Hoelzle

My M104.980 has an original label that quotes Bosch, Beru and Champion spark plugs, together with their aftermarket part numbers. So, these are MB recommendations.

I currently have Beru, with an MB star, from the main dealer.

I have used aftermarket Beru, Bosch and NGK. Always the correct part numbers cross-referenced from the MB number. The MB EPC lists 3 MB numbers corresponding to Bosch, Beru and Champion aftermarket numbers.

No difference between them (over the 23 years I've had the car) so don't get too hung up about Bosch.

My last 2 batches of Berus (MB and aftermarket) were made in France.

My engine is the M104.980 but I think the later ones may take the same plugs.

Good hunting.

RayH

Ray, 20 years ago an experienced MB-trained tech advised me to use Bosch F8DC4 spark plugs in the M104 engines. Who would know better than an experienced tech who worked on that vintage MB vehicle regularly?

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Fred Hoelzle

Haha. Possibly the people who stuck the label in my and many other cars. He was told what to do by the MB management at Stuttgart. And he was probably German so very good at following orders!!

Just fit good plugs of the right spec.

R