SeanR1700

Hey friends, I have a 2005 S55 AMG currently at ~108k miles and I have finally decided to change the spark plugs/wires. I had a couple questions about this.

Firstly I remember reading that the process is much easier if you have a particular tool they make especially for replacing Mercedes engine spark plugs, however I was unable to find one that definitively said it worked for the M113K engine. Would anyone happen to have a link to the particular tool they are confident would work for the engine in my car?

Also I read that these engines are very particular when it comes to the brand of spark plug you put in it. Does anyone have any recommended brand/plug that I should use with this engine?

Not to get to greedy in my questions but I should also ask if there are any non-obvious high mileage maintenance items for these engines that I might not have thought to do. I have replaced the super-charger pulley bearing and replaced the super-charger oil along with both belts around 100k miles. Have I missed anything?

Thank you very much as always for any help, this knowledgeable community has been a great asset to help me enjoy this great car.

kyosuke

i bought this one

and used these

E42AMG???

2309 spark plugs work good with stock motor and are good to have if you decide you want to do smaller supercharger pulley. Summit racing is the cheapest place to get them.

Wires dont need need to be replaced unless they go bad which is very rare.

I like using these better than the "special" tool
https://m.harborfreight.com/3-piece-...ers-37909.html

SeanR1700

So these are the spark plugs both of you are recommending?

https://www.summitracing.com/parts/ngk-2309

E42AMG???

Yes

sakodik

Yup, used those 2309 in my tuned s55.

SeanR1700

Would they work just as well for a stock engine ?

E42AMG???

This

GrepAwk

That harbor freight tool recommended above is good. You basically need something to reach down into the hole and grab the base of the spark plug shield near the bottom and twist it a little a little left and right to pull it from the socket. The wire comes up with it.

I replaced with the recommended OE plugs (2 per cylinder) and didn't waste money on the split-fire or multi tab plugs.

While you are doing plugs, you should also address any oil leaks in the valve cover gaskets, if you see any evidence or leakage

SeanR1700

I bought the specialized wrench like a sucker and got the 2309 NGKs as well.

My mechanical abilities are no where near being able to deal with valve cover gasket leaks, what are the tell tale signs I should be looking for?

GrepAwk

Well, at least you are saving lots of money with DIY and own a nice tool with the savings.

Tell tale signs of VCG leak? Oil seeping out and coating the outside of your engine around your spark plugs and ignition coils. If they leak near the rear, oil can work its way down around the bell housing and drip through to the bottom.

If you don't see lots of oil on the sides of the engine around your spark plug holes or the ignition coils then don't worry about it for now. It's not a hard job. Unbolting, removing, cleaning, reforming new gasket from RTV squirted out of a tube, then careful reassembly.