mcypert

Actually, this isn’t about how to replace your spark plugs…But, to get to the plugs, you must remove the coil-pack… So, having done so, I thought I’d share…

I didn’t need plugs (they were fairly new) but I was getting a P0300 misfire code and I sought the help of the forum on this thread:

https://mbworld.org/forums/s-class-w...tion-data.html

With the helpful advice given on the forum, I concluded the left-side (driver’s side USA) coil-pack was the culprit. If I’m correct, 2751500580 is the left coil the 2007-2008 V-12 was born with. Google search shows it’s available for about $850, but it’s not. 2751500780 is the only # really available as a new part and best I could do was about $1K for a new one. $1400 retail! You can get used ones or have yours rebuilt for around $700… See thread above…

But, to replace your coil pack or change your plugs, here’s what’s involved (If your going to do much work on your MB, you need star sockets and Torx bits):

1.Remove the 2 covers shown in pic 1. They’re not bolted down… just pop straight up, more or less (my car had only seen the Dealer before me… and I had one broken tab… so, even the techs get this wrong!!!)

2. Remove the air-box that houses the air-filter in pic 2. (Surprise, you don’t even have to remove the air filter, but you might want to… mine had bugs, leaves and sand inside.) Air-box has 3 star-socket screws, and 3 air-fed connections that just pull apart. Also remove the electrical connection toward the center of the engine (squeeze at bottom to release).

3. Remove the aluminum, coolant-fed, intercooler in pic 2 and pic 3. (I found it really “cool”, pun intended, that MB uses a liquid-to-air intercooler. I’ve had a couple of turbos and they had air-to-air intercoolers. I wouldn’t have know MB uses liquid-to-air cooling but for attempting this repair.) Again, 3 star-socket screws secure the intercooler, but then there’s the coolant lines…Use pliers to remove the clamps… Good news is you’re at the highest place on the engine, so air accumulates at the top. The tire-valve-style bleeder valve should help you allow air to flow in and minimize coolant spillage. Just remove the black cap, press the pin with a screwdriver and allow air to be sucked in… I had no spillage when I removed the hoses until I curiously turned the intercooler upside-down and looked inside… Blue stuff on the garage floor… but not much. There’s 3 hose claps to loosen to complete the intercooler removal. There’s also a clip bracket for an unrelated electric connection on the back of the intercooler… It just pops out.

4. Remove the aluminum pipe that runs from the turbocharger up to the intercooler (not shown). One screw holds the pipe to the turbo with a “C” shaped clamp… and amazingly, all star-socket screws from air-box to coil-pack are the same size!

5. Disconnect the electrical connection to the coil-pack. On the left side, the release mechanism for the connector is on the left-side (topmost) of the connector. Use a screwdriver to slide the locking mechanism toward the center of the engine. The locking mechanism slides out about 20 mm. See pic 4. On the right-side coil-pack, release is on the bottom…

6. Remove the coil-pack. There are 6 screws securing it and 1 extra screw that secures wiring. The coil-pack is a tight fit. I found getting #12 out first, closest to the firewall, worked best for maneuvering the coil-pack out of the engine bay…

7. Most of the red insulators, that are supposed to be inside each of the 12 coils, will stick to the spark plugs. They are easy to pull off the plugs with needle-nose pliers. Just shove them back in the coil-pack tubes, fat-side first…

If you need to replace plugs, you’re there…Simple from here…I found sets of 24 iridium plugs quite reasonably priced on a Google search…Not so, coil-packs for the V-12….

First attempt to get the coil-pack off, and back on, took me about 3 hours. Can probably do it in an hour now.

Hope this helps…. Thought it might, being W221 MY V-12 specific…Mine is a 2007, but I think it’s the same ‘til 2013 for the V-12…

Regards….Mark

alx

Thank you for taking the time. Another nice write up with pics.

UNderdog

Nice write-up thanks for taking the time. The water lines for the intercoolers do not need to be disconnected though. Once the bolts holding the intercoolers are removed and the electrical connectors are popped out of the bracket on the back, simply lift them up and tie-wrap them to the underside of the hood through the front bolt hole. You will have plenty of room to work under them and no risk of air entering the system.

mcypert

Nice Underdog:

You've obviously done this more than me... exactly once for me... Or, you're much better of solving the puzzle of the V-12 compartment than me...

Anyway, thanks for the hint.... We need all the help we can get....

Everyone take note... If you don't need to disconnect the coolant hoses, you'll save a ton of time...

Regards... Mark

tusabes

Did the new coil and plugs solve your random misfire problem ?

mcypert

Yes, the coil pack fixed the problem. Didn't need the plugs as they replaced not too many miles ago...

tracvision

Good write up and pix. You definitely do not need to remove the intercoolers from the car. Just remove the 3 star screws and flip them up easily against the bonnet. A bungee will hold them there. There are some clip on wires on the rear that should be removed first.

Clark Rupp (v12icpacks) did my coil pack for $700.00. I would recommend this route as he uses higher end components than MbZ and he tests each unit.

Also, a big issue with Coil pack failures, is leaking valve cover gaskets. If you find oil down in the spark plug well, this will cause the individual coil packs to short. There is no better time to replace the valve cover gaskets than now.

Polar Bear

The WIS documents actually also recommend not unclamping the coolant hoses due to inducing air into the system. If this happens, there is a procedure to bleed all of the air out of the coolant system afterwards which is a little time consuming. You can find the WIS document here:

https://resources.mbdx.us/files/pdf/...Coils_M275.pdf

I hope this helps!

johnnyrocket52

Thank you Mark, your procedure is spot on for removing the coil packs along with the suggested idea of hanging the intercoolers out of the way with bunji or tie wrap and not breaching the cooling lines.

My question is: when the new coil packs arrive, do I remove the rubber inserts and install each one onto each spark plug, then install the coil pack?
Or, do I leave the rubber insulators installed in the coil assembly and install the coil pack assembly in one shot?
Thanks in advance for a solid technique.

Also, is there any safe lubricant to ease up the tremendous stiction of the rubber insulator to spark plug? Sometimes alcohol makes things slick and then evaporates away leaving minimal residue? Sounds risky…

Johnny

mcypert

Hi Johnny:

If I recall correctly, you stuff them (the red insulators) back in the new coil, and install using the same angle used that you used to get the old CP out. It's been a while...

I didn't use any lube to reinstall, but dialectic grease may not be a bad idea...

Glad this post helped.

To other friends and members: Johnny's Q reminded me, I haven't been on the forum in a while... All good, and I've been meaning to post about my V-12 Cat-Back exhaust adventure... All is good, and I'll report soon...

Regards... Mark from South Padre Island, TX

johnnyrocket52

Thanks Mark. It makes sense. The rubber insulator hits a hard stop when inserted into the metal tube, fat end first. When they were pulled out , the rubber ended up everywhere in the tubes from the pulling action. I over thought about it after seeing that. I suppose wiggling the new coil pack down in the holes starting with the rubber insulators inserted to the hard stops, and the mounting bolts pull the pack assembly flat, it will all be just fine, I believe?

Everything I’ve read to now is saying go ah natural and don’t use any type of lubricant as it might attract contaminates and lead to arcing. I think I’ll stick with the old family recipe…

Johnny

mcypert

Worked for me... No issues for, what?... 6 years...

johnnyrocket52

Thanks again

johnnyrocket52

I completed the job of replacing all 24 spark plugs NGK 5648 IFR6Q-G and both coil packs from Clark Rupp https://www.v12icpack.com/

The old spark plugs were gunked up heavily with anti seize stuff. More is not better. Removing them was like they were lock tighted.

Found oil in half of the spark plug wells. Found most of the valve cover gasket spline screws were loose. Torqued them all to 4nm and cleaned up the oil everywhere. Could not wait for new valve cover gasket.

Replaced all of the spark plugs. Verified each plug’s gap was 0.70 mm. Torqued each plug to 20 ft/lbs and did not use any anti seize.

Installed left/right coil packs by pushing them on most of the way and then letting the mounting screws seat them in the last 10-15 mm. Did not use any lubricant at the suggestion from Clark.

Old coil packs didn’t look too bad at 77k original build 08W23. There was a little bit of oil on some them but no evident arcing or melted components. Shipped those back to Clark for core charge refund.

The complete job took me about 2 days out in the front yard. I was delayed by 3 hours because I thought a dropped spline screw fell into the outlet of the turbo. A friend was en route with a fiber optic viewing scope to look deep in the turbo. Took the belly pan off in the meantime and after extensive searching the FOD was located. Whew. After that I promptly taped up every hole I could potentially drop something into.

The drive afterwards demonstrated instant acceleration. Before there was a noticeable delay. Torque was now consistently pulling and smooth. All around improvement in engine performance from my perspective. Worth the knuckles busting experience, and oh, saving $5k in labor fees from MB.

I’ll keep an eye on the valve cover screws tightness and oil leaking out and this ignition PM and upgrade should last way beyond the MB stock offerings.

Johnny

mcypert

Nice job, Johnny. Thanks for contributing.

One Q: Why the coil packs? I have original on one side and new replacement of the other. I replaced the one CP because of P0300 code. I was mostly guessing, on the need for a new CP, but I got it right on the first try. 6 years later, all is good. Plugs recommended at 60K, so I get that. Oil in the plug wells is bad for the coils, for sure. Just wondering if you had any other reason to replace CP's, or was it just one of those, "while I'm in there..."?

Regards... Mark

BOTUS

does it go even better with Super-unleaded high octane fuel - ideally without ethanol death additive ?
dose this one have the water air intercooler things that you need to check top-up the nearly always empty expansion bottle ? if so its hidden under the engine cover

never leave inlet / outlets for stuff to fall in - biggest concern with VGG guy - its just madness and no need to be so risky

vettebk

WTG, this is very good. What about the Voltage Transformer?. Presume that is also original but I could be wrong. It is the square box on top of the engine and sends power to those new coil packs. Clark's stuff is really good.

johnnyrocket52

Just got the car with 77k miles, my only daily driver, it must be reliable, and fun. I decided to swap out the coil packs after reading about the finite life designed into them by MB. Design to failure. Generate future business. You all come back now, yah hear? My build date for coil packs was 08W23=2008. I didn’t want to end up on I-5, replacing them in the rain. Why is the tungsten light bulb still lit in the Smithsonian for over 100 years? Because the tungsten filament was made really thick, and it’s left on all the time. They figured out to make it thin, and you buy light bulbs every 3-5 years. Man’s first attempt at design to fail. The data shows the coil packs die eventually mostly around 7 years/70k miles, whichever comes first. Slowly degrading until codes get thrown when they really start to go. It’s kinda of like antifreeze, 5 yrs/50k miles, whichever comes first. The antifreeze protection will drop off a cliff. That was my thought process.

Johnny

mcypert

Johnny... Got it...

That's some pretty pricey maintenance, but you got 2 for 1 over retail on the cost of the CP's and your plugs were due too. My CP experience was p0300 code, but no discernable change in performance. The problem didn't leave me stranded, and I drove about 1000 miles with the intermittent issue. As mentioned, I was mostly guessing on the cause, but with some input from the forum, it Was the CP. I sent my defective one to Clark. So, maybe you now have my old one in your car, but better than new from all reviews...

Good Q’s, BOTUS:

1) I always use the highest octane I can get, which has about 10% ETOH in Texas. I wonder if the MB has knock, and other, sensors that will dial it back if you use the cheap stuff? You can probably run 87 in the turbo if you put an egg between your foot and the accelerator... hammer it, and you'll break the egg and the pistons. But, yes, I think she runs better on Premium...

I used to occasionally run 87 in my Stealth TT on long boring, highway drives. That TT had a boost gage, and at highway speeds, it never ran any boost. My theory was, at 8:1 compression, hi-octane fuel is just a waste of money. BUT… in the Merc, spool up the turbos and you’ve added 20+ psi of boost, and effectively increased the compression to where it would be a sin (if not a catastrophe) to send 87 octane into the cylinders. For that reason, I wish the Merc had a turbo gauge and I’ve thought about adding one… It would be neat to see where the boost starts, and how much throttle initiates positive pressure…

2) I don’t think I've ever had to add any coolant. When I unnecessarily bled the intercooler to get to the CP, I just used the Schrader valve to let air in. There's a second filler cap at the back of the engine, under the engine cover, as you said. I used that and the Schrader valve to get the air out of the system, with no issues. It never even occurred to me that I might be creating a problem-- by introducing air into the system-- until others pointed out the draining the intercooler was not needed-- just hang it out of the way. Anyway, not sure of how the plumbing is routed, but it seems to circulate through the intercooler pretty well.

The amazing part is that hot coolant-- like 90C -- is considered "cool”. I guess, compared to exhaust/turbo temp, it is!!! It has also occurred to me, that it might be possible to get some wild HP out of the intercooler, if one were to add a separate "chiller" and bypass the engine's cooling system altogether... But, as anyone who has worked on the V-12 will tell you: Where the hell would you put it???

Regards… Mark

BOTUS

boosting air makes it super hot - so 90C is both much cooler than boosted air and its a stable temp - so you can tune to match a standard = much better

remember / try pumping up a bike tyre with a aluminium bicycle pump - you burn your fingers if you go at it fast

In the work described in this paper, a water-oil-cooled turbocharger was extensively instrumented with several thermocouples on reachable walls. The turbocharger was installed on a 2-liter gasoline engine that was run under different loads and different heat transfer conditions on the turbocharger by using insulators, an extra cooling fan, radiation shields and water-cooling settings. The turbine inlet temperature varied between 550 and 850 °C at different engine loads.

its also why its essential after ripping it, that you allow the turbo to cool down by idling for 3 mins or so with the oil circulating - this allows the oil to take away the heat from the impeller bearings before the oil is burnt to a crisp - it can really only do 350C for short duration's - turbo timers are often on kids cars for good reason... the hope to keep it circulating pumps the manu sometimes fit, that pretend to work with the engine off usually fail in no time at all.... 350C is max short duration temps for posh synthetic oils - joke oil is toast at 200C

https://www.sae.org/publications/technical-papers/content/2013-24-0123/


.

BOTUS

my evo had an air to air cooler - and a factory fitted button by the gear lever - to spray windscreen washer bottle fluid on to the outside of the intercooler for fast starts :-)

I wound up the boost one day to 1.3 bar ripped it off the line great for all of 4 seconds and then popped the HT leads - as a spark under big boost is much harder work... its why the v12 pops its clogs if you rip it - its easier for nature to find an easier root to earth than inside a high compression environment....

johnnyrocket52

I’ve owned many boosted engine automobiles as well. Old and new. 2005 Dodge SRT-4 2.4 liter Mitsubishi closed deck motor with a Mitsubishi turbo capable of 18 Psig boost with Stage 2. Not direct injection. Premium grade gasoline 92 or greater only. It had a 100 octane button on the dash. Fill it with 100 octane, click the button, and 15% more power. Turbo was mounted in back on top of motor. Bearings were engine oil and water cooled. In the book it says ah: after spirited driving (aka hammer time driving) it is highly suggested to drive the car around (or idle it) for at least 3 minutes to give the turbo time to go from red hot, back down to engine operating temperature. My readings: if you do not do this suggestion above, ride it hard and put it away wet, just only a few times, and you will coke (aka melt oil) the turbo bearings, and Wah lah! It dies!
So, after spirited driving, manually cool the turbos back down or invest in a turbo timer?

Our newer car with the Ford Eco boost motor, direct injection, and twin turbos are tucked close under the motor and exhaust, just like the S600. Ford states for faster cooldown after spirited driving, so no cooldown time is necessary. I still idle for 3 minutes after hammer time if I’m parking for the night.
Maybe the S600 was designed that way with the turbos tucked up low under motor before the Ford and they shared some knowledge? But the S600 is not direct injection, which is part of enabling the use of lower octane fuel without knock, translating to engine damage.

Ecoboost is direct injection, you can run lawnmower gas 86 octane, boost it, and the timing has enough range and the direct injection makes it possible for the motor to operate without damage. The owners manual says it designed to do that. It also says: to realize maximum performance of the Ecoboost motor, premium grade gasoline of 92 or higher octane is recommended.

By all indications the S600 should run high octane fuel only. Damage is eminent if low octane gas is used and the engine gets boosted.

If the recommended 92 octane fuel is being used, turbos can die without a proper cooldown cycle immediately after spirited driving evading the authorities.

Johnny

SilverV12

Circling back on this one as I'm knee deep replacing the plugs. I've got my driver's side coilpack off, all plugs replaced.... and now I can't get the damn coil pack back on!! seems like the tubes are stuck and not going in.... any sage words of wisdom, gents?

thanks

vettebk

Check to see if you have one red silicon insulator per plug/coil. Sounds like you have an extra insulator blocking the cassette from sliding on the plug. Keep us posted.

SilverV12

Great thought! insultors all seemed good, so reused them all... don't think any are doubled up as i used needlenose to take every one off (they all stuck to the plugs). Will have to try again tomorrow.