grane

After the super service you did use Techron as directed to keep enginegine running properly.

Search on this board tpo see the Bulletin on V12s fuel system contaimination and bad Sunoco gas.

Use Shell 93 when you can.

NEMES1S

can plugs getting close to the 5 year 50k range cause your car to surge? I replaced filters and try to maintain it by merc specs but it is surging just a bit under partial throttle

abiazis

They recommend changing plugs in V-12 every 5 years.....regardless of mileage.........I did and happy I did as car running fine now...

KendoBoo

Getting ready to install a new set of NGKs. Does anyone know where to get the correct spark plug gap setting? I know that some times the gap can get changed in the shipping of plug and would prefer to verify the gap before installing them. Thanks

abiazis

Not NGK, but here is info on Bosch OE Type Platinum Spark Plug

Double Platinum, 14mm Thread Size, 19mm (3/4") Reach, 5/8" (16mm) Hex Size, Gasket Seat, Interference Suppression Resistor, Platinum Tipped Center Electrode, Platinum Tipped Ground Electrode, Solid Terminal Nut, .040" (1.016mm) Gap, Heat Range 7

Bosch uses a platinum center electrode that's heat fused into the extended ceramic insulator. Bosch platinum series spark plugs reach self cleaning temperature faster for quicker starts, smoother acceleration and increased fuel efficiency. The tapered, v-profile nickel ground electrode provides improved starting in cold weather and increased fuel ignitibility.

abiazis

NGK information........gap is different........

Extreme Long Life Laser Iridium Plug, 14mm Thread Size, 19mm (3/4") Reach, 5/8" (16mm) Hex Size, Gasket Seat, Resistor, Removable Terminal Nut, Projected Tip, Iridium Tipped Fine Wire Center Electrode with Platinum Tipped Tapered Cut Ground Electrode, .028" (0.7mm) Gap, Heat Range 6

NGK iridium plugs represent the ultimate evolution of spark plug technology and performance. The iridium center electrode is both stronger and harder than platinum. This tapered cut iridium center electrode reduces the voltage requirement for spark. This allows for a brighter, stronger spark from your existing ignition system. A platinum tipped ground electrode further contributes toward the extreme longevity of this plug.

NEMES1S

I looked at NGK's site and they said not to gap them, but if you are planning to, you need a special tool to do so as the old gapping wedge will damage the electrode. MB techs say .8 mm and other places online suggest .7 mm. Mine were in the .6 to .7mm range so I left them alone for fear of damaging one. btw spark plug torque is 25 Nm and the coil module are 8 Nm

KendoBoo

Many thanks gentlemen, the response was more than expected and very informative.

It is obvious that Benz owners are a cut above, and in this case very helpful to others in need.

I will put this new found knowledge to good use.

Thanks Again !

NEMES1S

and also another word of advice, there is a map sensor attached to a tiny hose on the passenger side intercooler (sensor is on a bracket on the center of the engine), be sure to remove it from the bracket/harness and leave it attached to the intercooler as it will break off (costs about 45 for a new one, cheapest sensor on a benz it seems like) and after you break it off, the little hose clamps can be a nightmare to put back on.

NEMES1S

and for the rear plug on each bank, I suggest using a spark plug socket on a shorter extension to get it back there, then use a ratchet with another short extension, you will see what I mean when you get in there, it is a tight squeeze and didn't appear possible with a single long extension.

KendoBoo

Many Thanks for the tip Nemesis.

Got to experience the MAP sensor when I had to change out the coil packs. Did have the correct plug wrench when I pulled the plugs then. Had put in E3’s with poor results.
Shop recommended I go with NGKs. They were not "really" sure what the best gap sould be.

Do you believe that “Indexing” the plugs is a good practice on this type of engine?

Thanks

NEMES1S

with 2 plugs per cylinder, I'm not sure it's really a huge deal, but some people swear by it

biker349

what is indexing plugs?

abiazis

Good write-ups on the web on indexing....

KendoBoo

Hey Biker349,

In a nutshell, Spark Plug Indexing is the art of lining up the open end of the electrode of the spark plug end, opposite of the bridge, and having it point to the center or top of the piston when it’s at TDC. The concept is to have the flame front of the gas/air mixture burn from the center of the cylinder outward and to have the explosion hit the top and center of the piston to force the piston down evenly as it burns to produce the best power per stroke and least sideways force on the piston or knock.
It requires that you mark the top of the spark plug so you can tell which way the open end is turned when you torque the plug into its final placement.
It will sometimes take a couple of tries and possibly different plugs tried per cylinder to get the correct alignment on all cylinders. Having extra plugs comes in handy.
It is a common practice in racing because of the performance different and sometime is required because of piston/cylinder head clearance of high compression engines being such close tolerances. Especially in Hemi type pistons or heads with extra large valves.
There are many web descriptions on this practice and many recommendations on the best alignment for different engine builds.
Hope this helps.

biker349

KenDoBoo, thanks for the great write up. from what i've read, indexing does not appear to give much gains for the daily driver, racing might be a different conclusion. am i correct?
thanks

KendoBoo

I wouldn't say that, the payoff would be a good running engine, better fuel economy, longer engine life (because of the controlling of the knocking, but the engine electronics does most of that already) less wear and tear.
It does take about twice as long to fit the plugs but I believe it’s worth it.
I like to take my time when doing maintenance anyways. Some engines have a knack of be just as enjoyable on the bench (being fine tuned and worked on) as driving.

I just finished my S600 V12TT and it took 5.5 hours instead of 3.5 hours. I just got back from the test drive and can tell there is improvement already. I get less surging, the V12TT is known for surging, and this seems to have improved it somewhat.
At idle, I do not feel any misfiring at all. But new plugs will do that for about 5k miles.

NRL

Here are some pics of session changing out the spark plugs.


Clean as a whistle, make sure you clean out the cavity holes


Special Mercedes tool makes it easier to remove coil packs

AmorSrdanovic

did you change the plugs yourself? i have a little misfire problem with my s65

shardul

iTrader: (1)

i changed out my plugs 2 weeks ago, it was not that bad. but took a lot of time.

KendoBoo

Just a quick update to my earlier post.
Since I did the work last year, my S600 V12TT is STILL running strong.
I feel the results have been better because of the plug indexing. Those brave enough to do this job on their own. I salute you ! Take your time and enjoy the knowledge that you gain while doing any work on your ride, and find time to enjoy the money saved by not getting bent over at the MB shops.

Flight Test

NRL, what material did you use for the reflective barrier on the bottom of the intercoolers?

I was thinking of putting some DynoMat that I have on mine but was a little nervouse how the sticky adhesive would last getting so hot in the engine compartment.

jatko

New to the site and new to the s600 TT but not new to Mercedes. I have learned from my mistakes which have cost me plenty of $$. Removing the spark plugs are relative easy if you go slow and carefully, At least the right side is.

You must removed the air filter housing (3 bolts) , disconnect the air flow sensor plug from the housing. disconnect the aluminum feed tube from the turbo to the inter cooler- this has two hose clamps near the inter-cooler and one c shaped retainer bolted to the lower part near the exhaust manifold. There is a large O ring which should be replaced inside the lower housing of this piece. There is a vacuum line connected to the right inter cooler which connects to a Very important sensor- intake pressure (controls the turbos) . I lifted up the inter cooler up and broke off the nipple ($50 mistake).
But if you lift the inter cooler up a bit it provides far more clearance to remove the coil packs.
There are 7 bolts which hold the coils - so remove them and gently pry the packs out VERY SLOWLY. Nobody really tells you about the red rubber boots which insulate the coil and the plugs. But in my case these rubber boots were stuck to 10 out of 12 spark plugs and a ***** to remove. I suggest replacing all 12 boots, 2.99 each at Auto Haus ( 0001590080 /Spark Plug Connector).
Also I would suggest cleaning up the head where the plugs insert prior to removing the plugs, oil dirt and all kinds of other crap is in there and was a secondary reason the car misfired IMO ALSO**(cover the two large ports below- both lead directly to the turbo) before starting cleaning. I also suggest using dielectric grease on all the red boot interior when re installing and some sort of RV sealant on the interior to hold the boot inside the metal tubes.

This may sound like common sense to many of the more senior members but I searched and search for this info and had to learn it the hard way.
I hope this helps some of the NEW DYI working their S600. BTY I used Auto Lite double platinum plugs at $4.50 each. The master tech at the dealer said they will last longer than any coil pack, thus the reason.