Misfire on cylinders 7-12
 

Greeting! New sucker here who just had to own a boosted V12. I've read quite a bit on the engine and car(2008 S600) and decided to pull the trigger just a few days ago. I got on it a bit last night and now have CEL showing a misfire on cylinders 7-12. My first thought is that the coil pack on the drivers side is toast but I wanted to confirm before I replace it. Is there anything else that would throw a CEL for all of those cylinders misfiring? I ordered a better handheld reader since mine is basic and not specifically for MB. I'm planning on buying a STAR unit in the not too distant future. Any help is appreciated. Thanks! :cheers:

Transformer a better place to start? Edit - Yep, looks like the transformer will be taken apart tomorrow.

http://www.v12icpack.com/

I finally got around to taking it a part today. It turns out that the drivers side coil pack cable just came off! WTF! I re-seated the connector, cleared the codes, and the beast is running again. I guess I'll just have to watch it and if it comes off again, maybe a well placed zip tie.

great info, thanks

Well, I started her up this morning and the misfires came back. $#%*! I'll dig into it when I get back from my travels.

I rented a VT from http://www.v12icpack.com/ and that's exactly what it was. Runs like a champ now. If anyone is wondering, Clark(v12icpack.com owner) has been nothing but great. He's fast, friendly, and willing to answer any question I had. Highly recommended.

Thanks for the heads up. Have a misfire in cylinders 5 and 6 on my S65. Gonna check the plugs first but if it's the coil pack, will get a rebuilt one from Clark.

Hello
I own a cl 600 for over 3 years now.
LOVE HATE
And let me tell you the misfire 0n the coil packs are something that comes and goes.
If u are stuck in limp mode try to cycle the key.
Most of the time this works for me if its not to angry.
And yes i have 2 new coil packs from MB with less then 20k lifetime warranty.
And a new Transformer Too.
I think its par for the coarse!
But that Clark guy is good. tried to help me when i blew transformer.
Rob

Do you know the part number of your spark plugs?


Nick

First post at MBworld.com....
I have a 2007 S600. I just had the same happen to me, 7-12 misfire. I had been having sporadic misfire/knock about every other month for about a year when at very low RPM (such as when going slow at a drive-thru). When this happened I would get a flashing CEL and would turn off the engine and back on and I would be fine for about another month or so. I had the transmission re-built in Nov 2017, and I thought the misfires were related to failing TCC (torque converter clutch) not dis-engaging and putting the engine in a bad state and mis-fire on both side. I had the TCC solenoid replaced about 2 month after the transmission was rebuilt (TCC was hard engaging), and I hadn't had much issues with misfires since. I did have a CEL that was due to fuel vapor vacuum line and didn't think much of it.

Finally, while driving on the highway last week about 30miles from home, my dash light dimmed and it seemed that my transmission was not shifting properly (CEL had already been on due to fuel vapor vacuum line). Acceleration was weak, but I was able to continue cruising at 80 on the highway, had no drop in MPG (from what I read on v12cipack.com it seem that cylinders 7-12, left bank, are shut of during cruise, which would explain no drop in MPG if true). I figured if the car is drive-able, and my CEL wasn't flashing I would try to make it home. I made it home fine and pulled the codes; reading P300, P307-P312.

After reading this thread, I was inspired to start taking things apart instead of taking to an INDY, figuring I would save >$1000 on labor alone, and I could source parts cheaper than they would sell them to me. So I started unbolting and removing things. After reading on v12icpack I thought I had a bad voltage converter and decided to open it up to see if there was anything obviously wrong/burnt, but it actually looked good inside. I was able to price a genuine rebuilt part from about 3 MB resellers online for between $360-$420 (some dealers and resellers were as high as $850). Before ordering a voltage transformer, of which I read for a full bank misfire it is 50/50 between transformer and coil pack. There is even a place in Boca Raton, FL just an hour from me that does testing and rebuild of this unit (testing $120, and if it is bad they put that full amount towards the $300 rebuild service; see programainc.com for details). I figured I'm better of getting a new unit for $360 than risking a $120 test and then $300 rebuild. While trying to decide what I was going to do I decided I wanted to open the coil pack and see if perhaps I had a better choice to make (ie if the the coil pack was obviously burnt inside I would just replace that).

I removed the left coil pack (driver side). As an aside, my engine bay has been a dirty mess since I bought the car in 2016 from a guy in PA, but I was never able to find a detailer willing to wash the engine bay (they apparently gave up their advertised services due to liability when power washing electronics under the hood) and had thought it futile to do it myself, until I watch a video online of someone doing magic to a nasty engine bay with a rag and soap. So I started cleaning up and began with the outside of the coil pack. The first thing I noticed was a bit of rubbery gunk on the crevices of the plastic cover for the coil pack and tried to scrape it off. Initially I thought it was some dripped silicone that had gotten caught in the corners, but as I started scraping it off from the full length of the coil pack I started seeing cracks. When I finished removing it all, I pried the cracks open only to find that it was the repair job for someone who had tinkered with the coil pack internals. I saw a bunch of 'R's written on some components (suppose this meant repaired), and I also noticed that some of the metal tubes that hold the coils where different than the others. Immediately, I thought this must be the defective component and not the voltage transformer. Actually, the part number for this coil pack is 2751500580, which has been supplanted by new part number 2751500780. I searched high and low and found
one site selling 2751500580 for only $860 new (one of those common MB parts catalog webpages, like a site that is a template for MB dealers to use), though that same site sell 2751500780 for $1050. Miraculously, though, I found my local Coral Gables dealer selling the newer part number 2751500780 for $960+tax, which is the lowest I have found a retail place selling it for. They wouldn't even honor the online price if I went direct through their parts department, so I had to wait until Monday when the 'internet' guy was in to process the order, even though I would still pick it up in the standard parts department. (Seems that Cutler Bay Mercedes, which is owned by the same owner as CG Mercedes, does a price match). I also tried calling Mercedes of Miami, but they wanted to shaft me with the full retail of $1440, no even the standard 10%-20% they have given me in the past.

While my car was sitting idle I also decided to replace the oil pan gasket which had started leaking suspiciously after getting my transmission re-built and also asking that shop to install engine mounts while they had the car up there anyways. I THINK they probably jacked up the engine by the oil pan in oder to replace the mounts, and this must have squeezed the gasket out in places. And from looking at my oil pan it also seems there are stress cracks in the place that it would have been jacked up.

Long story short, I just replaced the spark plugs this evening and I'm going to do the coils this Saturday. The reason I came here is because after removing my plugs and putting a boroscope in the plug-holes I saw some fairly horrifying stuff. Seems the pistons are completely coated with carbon, and most of my spark plug holes appear to have oil on them as if someone has greased them up. Some of the plugs have crud on the threads, so I dont know if this is burnt oil that dripped from a leaky valve cover (only seems there is one spot that has a minimal oil leak that is of no concern), or is this oil that is coming from inside the piston chamber. Or could this be burnt anti-seize?

Does this look really bad??? What causes this? Can I pour a bottle of Seafoam into each cylinder and hope for the best?
My car burns about 2-3 quarts of oil over 5,000 miles, which I've been told is not terrible, but not good either. Apparently, for a manufacturer to replace an engine under warranty it would have to burn about 1 quart in 600miles, so I'm about double that. I also drive this car extremely hard.

https://cimg2.ibsrv.net/gimg/www.mbw...68252b4b10.jpg
https://cimg1.ibsrv.net/gimg/www.mbw...f9996a8601.jpg
https://cimg4.ibsrv.net/gimg/www.mbw...702f9b097d.jpg
https://cimg3.ibsrv.net/gimg/www.mbw...1c0e75c7bd.jpg

PS. I had decided to go with NGK BKR6EIX instead of the OEM part which is NGK IFR6Q-G. I think the former is a high performance part, and it was listed along with the OEM one as a being supported in an S600 on NGK's parts catalog page. Does anyone have an opinion on the matter? Also, see my prior question about cleaning the piston chamber with Seaform (or anything for the matter).

I also developed a sound coming from under my driver side, like metal clanking around inside a beer can. I think my catalytic converter is probably breaking up. Would this throw a code other than misfire if it was clogged up? Would using Seafoam to clean the pistons cause even more problems here? I see that I can buy a new Cat. for about $100-$200 online, and I'm guessing getting a shop to weld it in would be another hour or two of labor. Any thoughts here? How about straight piping it?

Wow, hell of a first post. Welcome to the forum! I think you're in the right place.

I would be cautious about using NGK BKR6EIX instead of IFR6Q-G. The V12TT is particularly sensitive to spark plugs, and MB specified the latter for reasons that we may not fully understand.

BKR6EIX are actually cheaper, and I think the reason is because of the nickel plated ground electrode, where the IFR6Q-G has iridium.

The latter is also has laser welded tip - it's a "Laser Iridium" spark plug, rather than an "Iridium" spark plug.

The IFR6Q-G also has a gap of 0.028", vs 0.032" for the BKR6EIX. I think that's another reason to get the IFR6Q-G. The larger the gap, the greater the voltage needed, hence the greater load on the fragile and expensive coil packs.

Therefore I think the IFR6Q-G is the better plug. Yes they're expensive, but they last twice as long; changing the plugs takes long time, and looking after your coil packs is particularly important on these cars.

https://www.ngk.com/product.aspx?zpid=9795
https://www.ngk.com/product.aspx?zpid=9330

Regards, Nick

Standalone thread for my project here https://mbworld.org/forums/s-class-w...ack-plugs.html

Hi Nick, thanks for the thorough reply! Ironically, I was not trying to cheap out, I actually thought I was doing myself a favor because for some reason I thought BKR6EIX were the newer technology. I think I fell for the marketing BS later in this post (perhaps I saw some sites selling them for more, seems that summit racing has them for $8.99 https://www.summitracing.com/parts/ngk-5648/overview/ whereas a few other sites have BKR6EIX for more).
The really fudged part of all this is that it listed all these plugs alongside what I thought/think is the NGK official calalog (http://www.partcat.com/ngk). Strangely enough, the site you link, www.ngk.com is not official, as under their search bar they state: "We are not NGK Spark Plugs USA. To contact them, click her" and when you click on the link to go to ngksparkplugs.com, the site is down, and has been since I went into a panic last night trying to find the specs on these plugs. Its actually quite pathetic for a site to remain down more than a few hours, especially with a generic 502 error and listing the OS that is it running on, hopefully their product engineers are more capable than the web engineers :(

If I go to what I think is the official UK site, https://www.ngkpartfinder.co.uk/car_...a.php?id=15535 and go through the product finder, it lists either IFR6Q-G or LPG1 as the 'LPG equivalent' only as an application for S600.
If I go to what I think is the official Canada site, http://www.ngksparkplugs.ca/part-finder.cfm, and go to the part finder, which ODDLY points to a different domain! http://www.partcat.com/ngkca (this is the same domain I found the parts from the US site last week).
If chop off the 'ca' reasoning that the US parts has no suffix and is http://www.partcat.com/ngk and searching for '07 S600 comes up with 5 part #s, all listing the same .032" gap (see pic attached). Actually, looking around the interwebs, seems that many site list IFR6Q-G as .032, and it isn't until I dig into the part finder product specs that it actually lists IFR6Q-G as having a .028" gap. The other noticeable thing I see is that the resistance on IFR6Q-G is 1KOhm vs 5KOms for BKR6EIX, and I read somewhere that the coil packs switch between 180V/23V to ionize air in the cylinder and measure some property that tells the computer how much gas to put in on the next cycle.

I believe last week that I fell for the first sentence marketing BS they had on the part description thinking 'combination of performance and longetivy' meant they had to sacrifice one for the other:
IFR6Q-G Marketing Description: Often specified as original equipment, NGK Laser Iridium spark plugs are the best combination of performance and longevity.
BKR6EIX Marketing Description: NGK Iridium IX spark plugs are designed specifically for the performance enthusiast.
It also lists the ground on BKR6EIX as a nickel core instead of just nickel plating, which is different from what you found. So I have no clue as to which website is accurate.

So most likely, yes, I got a less than optimal plug for my engine, but at this point they are in there and dirty (though I haven't put the coils on). And I doubt Amazon would be accept a used return (boxes already in trash).
When NGK USA actually decides to put their website back up, I'm going to call and complain that the part cat they link to has conflicting information on it and it and that is what I based my decision off of. I'll ask to exchange my current plugs with the OEM ones if possible. I'll post back up here if they respond. If they don't want to exchange, I may just use these for a while and then get the OEM part from FCP Euro, who has a lifetime warranty/exchange, meaning I exchange them every year if I want for free!

Thanks again, Nick!
https://cimg5.ibsrv.net/gimg/www.mbw...77a6d49da1.png

Official NGK USA linked catalog likely listing the pre-set gap for IFR6Q-G as .032", whereas digging in on this page to the part details lists .028" WTF!

Apart from the gap (which you can easily change), i would not worry too much about a slightly different plug recommended for the M275 by NGK.

Edit: other people say that the M275 is very picky about spark plugs so NGK IFR6Q-G or the Bosch equivalent only.

The OP asked for advice and my answer took into account the fact that NGK advise against re-gapping Iridium plugs.

Nick

I used NKG and have better results with Bosch 0242236571 FR7KI332S
and as Welwynnick says, NO iridium re-gapping, the Iridium coating will be damaged and your plug will smoke in less than 6 month's

Quick followup, after putting in the new LH coil pack, I noticed a bunch of hoses running to a box sitting ontop of the left side valve cover. Seems there is a nipple on it with no hose connected. Is something supposed to go into it? See pics at https://mbworld.org/forums/s-class-w...ml#post7481508

yes normal

be careful when you put the intercooler back passenger side
if you don't do it carefully you might break of a hose on these shutoff valves

Update on the NGK plugs. After leaving a message over the weekend, the product tech support guy called me back early this morning. He confirmed their site, ngksparkplugs.com, has been down, but that the media group handles that, he handles product support. We had a chat about their part finder, and he confirmed that looking at my car he was seeing that it lists 5 compatible plug types at .032" (see my prior screen shot). I explained that some sites, including their product details, as well as some retailers list IFR6Q-G as a .028", and he then confirmed that in their product spec sheet it indeed lists .028" as the pre-set gap. I asked if I could mail them my plugs and just pay the difference to exchange for the proper set since the unused and un-sparked plugs just sitting in my engine were already dirty and the retailer was unlikely to take them back. He said even if they wanted to do an exchange like that, that he had no way of charging a credit card, even for shipping, and then told me he was going to confirm the proper gap setting with product engineering and call me back.

He called me back about an hour later and explained the their info was indeed wrong for my model and the gap should be .028" as stated in the product specs for the OEM part (IFR6Q-G). So they are going to revise their website/part catalog and remove all the other plugs listed (they even had non-Iridium listed on the site). And he also told me that since they listed the wrong info and because I already had the BKR6EIX installed (thought I haven't started the engine, but I likely cannot return them) and would have to redo them, he said they are putting 24 IFR6Q-G plugs in the mail for me. I am totally blown away :) There are very few companies that have either good or common-sense customer service like this. [Then again, this is a tech support guy in Michigan, not some L1 'customer service' located in another hemi-sphere who is just reading a script. I really wish more companies, especially those that don't have a physical product (cable/cell-phone) that actually costs money to manufacture, would take a lesson on making customers happy.]

PS
If I recall correctly, he also stated that the ground electrode on IFR6Q-G is actually a platinum core, not a copper core as listed on the product details (or something along those lines, which leads to the increase in cost). I also asked about the resistance (1KOhm vs 5KOhm) and he stated that for the high-performance engines that indeed it should be the lower resistance, so they are going to remove all the plugs that aren't the same gap or same resistance (which basically leaves only the OEM part). I also asked about the the cross reference on the UK site (because I looked elsewhere when the US site was down) about using P/N LPG-1 as a substitute, and he told me not to look on other countries websites as those recommendations are specific to the type of fuel used in those countries. I didn't know this but apparently LPG (liquefied petroleum gas - propane/butane????) and CNG (compressed natural gas) is a thing they use in other countries to save money over regular gasoline? Though those plugs seem to cost about $18-$30 each.
Interestingly too, I asked about the resistance values having an effect on ionization generation and measurement to determine how much fuel is being burnt and he gave me a history lesson on fuel ionization sensors and who came up with the tech. Dude knows his stuff.
I also asked about soaking the plugs in Seafoam to get the carbon off and he said it was a bad idea, since even a little moisture getting into the insulator in the electrode can cause it to swell and crack.

Also, I added borescope pics of my properly firing engine half, definitely alot 'cleaner' than the misfiring side: https://mbworld.org/forums/s-class-w...ml#post7481501

NGK is a great company, I've used their tech support to find a cooler heat range plug for my nitrous 350z when NOBODY had anything, the cars were brand new. I had a rep go and find a suitable alternative, and give me part #'s for plugs that didn't even exist yet, and told me to keep an eye out in a couple weeks when production started, gave me some local (to them) vendors that normally stocked everything and would be able to process my order quickly. They are truly a good bunch of guys, and the fact that they are OEM plugs for almost every manufacturer at some point, means they make a solid product. I will run NGK plugs in anything if possible.

That's awesome that they are sending you $300 worth of plugs for free.

That's a great result, and all credit to NGK.

In a similar vein, you might be interested to read this thread. Biker went through a similar process a couple of year's ago with Bosch, who had the wrong spec plug for the V12TT in some of their online catalogues. They put it right straight away, but not until countless resellers had taken the Bosch catalogue as gospel and listed plugs like the fr7kpp33u+ with a 0.040" gap as the V12TT fitment.

I think errors like this have led to countless failed coil packs. That's why I always say to people to use iridium plugs with 0.028" gaps like the NGK IFR6Q-G or Bosch FR7KI332S. Maybe there are other plugs from Champion, Denso or Autolite that might be suitable, but I've never been able to positively confirm the right part number (sceptical as I am now about the reliability of any SINGLE source of information).

https://mbworld.org/forums/cl55-amg-...n-map-cps.html

The other thing about NGK and Bosch Iridium plugs is that both manufacturers say not re-gap them.

Regards, Nick

SL65 Engine light & misfires - Intermittent??