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S600 TT: time to replace ignition coil packs

8K views 54 replies 6 participants last post by  cowboyt 
#1 · (Edited)
Hi folks,

It seems that The Time Hath Come. The S600 TT lost an entire cylinder bank last night. Check Engine light came on. I know what this feels like, because last year, I had to replace the voltage transformer when one side of it went kablooey. I let it cool down and started it up again. All 12 cylinders...at first. So far, so good. Then...the engine started running rough, as if a cylinder were misfiring. Then it got rougher. I gingerly limped it home this morning.

Got it on SDS soon as I got home. Yep, misfires, all right. This time, there were cylinders misfiring on both banks. Ah, well.

I have one of Clark's newly-remanufactured voltage transformer from v12icpack.com; this was installed last year. My spark plugs (NGK Iridium) and silicone boots (Beru OEM) were replaced a couple of years ago and have perhaps 8,000 to 9,000 miles on them.

Got both ignition coil packs off; it really isn't that hard to do. Did it without breaking the coolant circuit for the intercoolers, thanks to some bungee cords. All 24 silicone boots are intact, pliable like when they were new, and for the most part, still red. Not seeing any oil leaks, as I had also done the valve cover gaskets two years ago when I replaced the spark plugs.

The ignition packs appear to have been made in 2009. The car just clicked over 175,000 miles, so it looks like it would be right about time to have 'em replaced.

Got an order into Clark at v12icpack for both ignition coil packs (this is for the "exchange"), so I'll be sending him my cores back. The other way to do it would've been to go to MBOemParts.com and get a couple of new ones for $1,102 each (free shipping), and for brand new ones, that is a pretty good deal. Rock Auto is currently out of stock on the new NGK-brand ones (I'd trust NGK as well as Temic). But watching Clark's video about the new ignition coils that he's having made for his business, this may be an even better ignition coil, longevity-wise, than the factory ones.



TL;DW: apparently the inner ferromagnetic cores corrode on the surface, contributing to the failure rate. Clark has new ones, using a new design for the core. We will see if my rebuilt packs have the new coils on 'em.

EDIT: this is one of the times when it's probably a good idea to disconnect the battery first. :)
 
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#2 ·
EDIT: this is one of the times when it's probably a good idea to disconnect the battery first. :)
Why ??

Just pull the relevant Fuse(s) :wink

I'd rather cut off a limb than ...................................................................... etc etc :devil

HTH,
 
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#3 ·
On a W220, it doesn't seem to be so bad. Hadn't considered pulling that particular fuse or set of fuses, though. Good point.
 
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#4 ·
OK, replacing the coils didn't work. I've still got misfires...but only after the car starts warming up...just like before replacing them. If the engine is cold, all 12 cylinders fire fine in nice V12 fashion.

The difference is which ones are misfiring.

I've got two voltage transformers, both rebuilt by Clark. With the first one, I have the following cylinders misfiring.

1, 2, 3, 4, 6, and 9.

This is somewhat different from before replacing the coil packs today. Before replacing them, Cylinder 10 was also one of the seven cylinders misfiring.

With the second voltage transformer, I have the following cylinders misfiring:

1, 6, 7, 8, 9, 10, 11, and 12.

I *might* have a third voltage transformer around here somewhere. I'll try to find it tomorrow morning. Time for dinner.
 
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#5 ·
Hi T, @cowboyt ,

Oh Poooooooooooooooooooooooooooooooooooooooooo :frown

Did you get the Coil Packs on the "Rental System" ?

Hope so :wink

Have a look at the Lambda Sensor Readings also check for blocked Cat !!

HTH,
 
#6 ·
Nope, I bought 'em, thinking that was the problem. Really, I don't mind spending money on maintaining my vehicle. The coil packs will have to be done at some point soon, anyway, so I figure, now's a good a time as any.

Couldn't find the third voltage transformer in this mess I call a house, so I put the first transformer back in today. All 12 cylinders started up, nice 'n' smooth, things were fine until 40 deg. C. on the temperature gauge. That's when things started running roughly again with misfires. This time, the following cylinders were affected.

1, 2, 4, 5, 6, 9, 10, and 12.

All this time, I was checking the Lambda Curves. Not sure how to read these, but they looked pretty smooth at first. I started the engine and immediately hit "START" on the Lambda graph. All but the yellow one gradually raised smoothly, until the initial "high idle" settled down to "low idle" after a few seconds. Then all but the yellow one started jumping up and down. Finally, at 40 deg. C., when the misfires started, all but the yellow line took a nosedive to the floor. The yellow one stayed dead-center all this time.

I'll upload some pics as soon as I can. This USB cable and my phone are apparently not getting along so well.
 
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#7 ·
OK, here are some pics. We'll start with the new ignition coil assemblies. Both of them are here, and you can see that I'm also using one of Clark's rebuilt voltage transformers, currently installed in the car. Using the bungee cords for the intercoolers avoids having to refill and bleed the intercooler system later.



Here's how the coil pack assemblies come from v12icpack. First the right side....



...and the left side.



Note that the ignition coils themselves have "V12ICPACK.COM" stamped on the side. This is Clark's new-style ignition coil that he talks about in his videos. The idea is to avoid corrosion and thus have them last longer.

They even come with the red silicone boots. How thoughtful. :) Actually, it's probably a good idea, since most people probably haven't done like I did and bought new boots a couple of years ago. Doesn't hurt to use the new ones, so I installed them as you see them. Kind of a nice touch, actually.

 
#8 ·
Now let's get to the problem. Yesterday, with the first transformer. Notice that Cylinders 1, 2, 3, 5, 6, and 9 are misfiring. As long as I didn't change out the transformer, I could clear the codes, restart the engine, and these same cylinders would misfire.




With the second transformer, the misfires shifted to different cylinders, namely 1, 6, 7, 8, 9, 10, 11, and 12.



You can see here that the car was up to operating temperature. Never has taken long with this engine.



Coming up next: today's results.
 
#9 · (Edited)
Here's the Lambda values. The yellow one (it's kinda faint in the pic) remains at a value of 450 mV and doesn't budge. I think the blue one also does the same thing. The other two (green and red) start at 450 mV and gradually climb up to about 700 mV. I had just started the engine and begun the Lambda test. Note that at about the 49 second mark, the green one starts fluctuating between 250 mV and 650 mV, followed by the red one, about three seconds later (300 to 700 mV). The fluctuations correspond to when the "high idle" after a cold start goes to the "lower idle".



You can see engine temperature is just a tiny bit above 40 deg. Celsius. At this point, all 12 cylinders are firing and things are smooth.



I restarted the Lambda test, as apparently it stops after 60 seconds. It took me about 30 seconds to figure that out. :) Look what happens at around 31-32 seconds! Both the red and green Lambda values drop to somewhere between 0 and 50 mV. It was right at that very time that the engine started running really roughly.



There's that Check Engine light! The engine coolant temperature is now visibly above 40 deg C, though still not by much.



And here's the output of the misfiring cylinders.
 
#10 · (Edited)
Hi Terrell, @cowboyt ,

Good work, I hope the SDS nay sayers who might be reading this can now see the importance of this bit of kit :devil

OK, let's start in order of some things ..................

TWC references = Catalytic Converter

This is looking to be a bit of a Bear, have a good look at the pins / connectors on the Transformer and Coil Pack Wiring first, perhaps a tweak and contact cleaner on the plugs if no obvious breaks of wire tails, or bad and dirty connections.

When you first start the (most) Engines, they are in what is called "Open Loop" Fuelling, the Revs are higher, (fast idle), and the fuelling is done from a set and fixed Table in the ECU. The Pre Cat Lambdas are not controlling Fuelling.

As the Temperature rises a little, then the ECU switches to "Closed Loop" Strategy and the Idle Speed drops, Lambdas take over control of the Fuelling .......................

This is where your Car seems to go awry :wink

Now, you are getting Lambda readings on 2 of them there that are jumping up and down, 250 / 300 up to 650 / 700 mV ........................

I'm sorry but I don't know which Lambda is which Colour, but .........................
If these 2 are Pre Cat Lambdas then that would appear to be normal behaviour, and the other ones, if Post Cat should be maintaining a pretty steady reading that indicates that the Cats are doing their job, these 2 Post Cat Lambdas are purely there to monitor the Cat Performance, they have no effect on Fuelling ;)

Green and Red should be hopping up and down between those Voltages quite quickly as the ECU switches (trims) the Fuelling "rich / lean / rich / lean / rich / lean / rich / lean" etc etc etc.

From what you are saying they may be lazy.

I would expect a little movement on the Post Cat ones, it does sound like Yellow is bad at least, so lets try another test ..................

Start with the Bank with the most misfire codes ..............

Take out the Pre Cat Lambda and see if the Engine runs better without popping misfire codes, if it does, could well be a blocked Cat, if Misfire Codes are still their look for Air Leaks on intake system / pipes.
What are the Fuel Trims reading ................ If they say Rich I'd be looking for an Air Leak, because when they say Rich, it means ECU has trimmed them to the Rich end limit of the fuelling tables, therefore the Engine must be running Lean = Air Leak / Fuel supply inadequate issue etc usually ...........................

Vice - Versa if they are at the "Lean" end of the Scale, it means Engine is running Rich = Air Filter / Intake blockage, Fuel Pressure gone high, drippy Injectors etc :wink

I hope this doesn't, but it's looking as if after all that you may have to just chuck some parts at it, at least a set of Lambdas, especially if they are the originals.

Have you tried ringing Clark ?
He has probably got more experience of this particular problem than I have, might well have come across it.

I'm all outta any other suggestions right now, hopefully the above helps, and apologies if I'm telling you a bunch of stuff you already know ;)

HTH,
 
#12 ·
Hi @tusabes ,

Yes, Lambda Sensors = Oxygen Sensors, (UK / USA parlance thing) :wink

HTH,
 
#13 ·
Went thru all of that on my S600 2002 a while ago. Would start misfiring after a short drive distance, i.e. going closed loop.
Restart the car, and everything ok until a short while, then at closed loop misfiring again.
The posted DAS faults of the misfire were always "TWC DAMAGE #xx" (THREE WAY CONVERTER; this means the ECU shuts down the overfueling cylinders to protect the affected cat).
Changing plugs, xfrmr and coil packs (I got lots of spares) did NOT fix it.
With a super tech indie friend reading the O2 sensors live showed abnormal and bad readings.
Looked with a camera into the cat, and one was partially (1/3) blocked (Didn't bother to look at the other one).
Changed all O2 sensors (both pre and post cat), and then took car for a long hard drive to "fire up" the cats again, and they actually cleared.
Has been running fine the second year now, so I assume the cats cleared up.
Moral of the story: Before changing coil packs check in DAS for "TWC DAMAGE" first (only DAS will find these faults).

BTW: If you scan for my nick here and "there" you will also find a trick to use spacers for the O2 sensors that have their own cat to cheat and fix the readings until the cats burn clean.
 
#14 ·
The car does have 175,000 miles on it. I'll bet they've never been replaced.
 
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#15 ·
Here's tonight's information-gathering results with SDS. And yes, Dave is right about how necessary SDS is for troubleshooting modern MB's. Doubting Thomases may wish to revisit their view. :wink

I didn't see anything in SDS for fuel trim, i. e. is the mixture rich or not, or perhaps I did see it and didn't realize I was looking at it. Just in case, here are pics of anything that looked like it might be relevant, e. g. adaptations, all that. This was shortly after starting the engine, so it wasn't up to full operating temperature just yet. Remember that the major misfire business started happening maybe 2 minutes after running, or with coolant temperatures at just above 40 degrees C, so I did this quickly.



Here's the color-coding for the Lambda (Oxygen) Sensors.

Before the cats, you can see the red is for the right side, green is for the left side.
After the cats, you can see the blue is for the right side, yellow is for the left side.



And here's the graph, taken a little bit after starting the engine. I took four of the 60-second snapshots.

In the first pic, you see that the red (right, pre-cat) O2 sensor is already fluctuating. The green (left, pre-cat) O2 sensor doesn't start until afterward. I also included a temperature snapshot. Interestingly, the engine is running a lot more like it ought to be even at coolant temperatures in the neighborhood of 60 deg C. This is a marked change from yesterday.



It's been just over four minutes, and the bucking and kicking isn't starting. I can hear and feel the occasional misfire, but the engine still sounds and feels much better than yesterday.

So, let's now take a look at the misfire (fault) count. You will see here that temperatures ultimately get up to 80 deg. C., and we're still not bucking and kicking like yesterday. However, the fault count for Cylinder Bank 1-6 is noticeably higher than that for 7-12. The exception is Cylinder 10, which is less than half of what the other cylinders are, but it's still higher than I'd like. Remember, the spark plugs (NGK Iridium, naturally) are only 2 years old, and the red silicone boots, ignition coil assemblies, and voltage transformer are all quite new.



So, that's where we are as of this evening, 9:00pm, GMT -4.
 
#16 ·
Hi Terrell, @cowboyt ,

I totally agree with @Kraut56 ,

If I were you I'd change all 4 Lambda Sensors, start Car, do not let it idle, just straight away go for a good thrash, "Italian Tune Up" :grin

Light them Cat's = (TWC's = Lambdas) up good and proper :devil .............................

Could very well be the issue :wink

HTH,
 
#17 · (Edited)
Thanks, folks. I will order them *today*!

EDIT: all four of them ordered and on the way.

This is where I wish we had a nice, good, long, steep hill up one of the mountains. I'm talking about a multi-lane highway/freeway with a nice, high speed limit. They have that in Southern California, specifically a stretch of Interstate 5 called, "The Grapevine".
 
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#18 ·
I have a nice long uphill road close to home that I use for "test and tune". Can't use it with the V12. I don't think the engine discerns uphill from downhill lol!

I agree. With 175,000 miles and no knowledge of when the stoichiometric sensors were replaced I too would do all four.

Cowboy, just curious, how much were the set of four? Think I may do mine as well. I am coming up on 80,000 miles soon.
 
#19 ·
Hi,

On Customers Cars I generally pay around £180.00 each for genuine, if it were my own Car I'd likely fit Bosch at around £80 each, can't be bothered with the universals 'cos you need to muck around wiring in the old plugs, and they aren't much cheaper :wink

BIG NOTE, as per usual, do not cheap out on these, cheapo Chinesium's usually make an MB run worse which I guess is no surprises there then :grin

HTH,
 
#20 · (Edited)
With shipping and sales tax--Virginia is one of those that collects sales tax on out-of-state purchases now--it was $312 and change for all four. Got the OE Bosch "made in Germany" ones from Rock Auto.

And to your other point...yeah, the M275 doesn't really seem to know what "uphill" means.... :devil

Chinesium? CHINESIUM?? Seriously?? I shall not sully Da Benz with that junk!

However, I did find this interesting. Apparently Denso, an OEM for at least Toyota and Honda and maybe more, also make these O2 sensors for our Benzes. I know Denso to make good stuff, too, having worked on Hondas. Perhaps the same type of O2 sensor is used in those cars as well?
 
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#21 · (Edited)
I pulled out all four O2 sensors tonight, and sure enough, they're the Genuine-MB ones. My guess is that they're indeed the originals. Given that they lasted 175,000 miles, that's pretty good. Such is the quality of OEM, and that's why I went Bosch.

But there's a little twist....

Turns out several stores have the incorrect sensor listed as "Actual OE" for the S600 TT; see this thread.

https://www.benzworld.org/forums/w220-s-class/3034032-do-your-o2-sensors.html

The rear ones that I got are correct. The front ones are not, so they're going back and getting exchanged for the correct ones. So, the rears are now installed as of this evening.

Yes, it does take a bit of manoeuvering, a socket extension, a universal joint, and slender-ish forearms to get those front ones out. The use of a proper crows-foot for oxygen sensors is paramount; I used Lisle's, as it's thick, heavy, and strong. The rears weren't as difficult; I don't happen to have a 22mm open-end wrench, but I do have a good-quality, 12" (30mm) long, USA-made Craftsman crescent wrench. That wrench got the rear sensors out nicely with just a bit of help from the rubber mallet.

Before I began tonight's work, I did start the S600 to get it up on the ramps so I could get under it. This was to get the rear O2 sensors out and just generally check underneath the car. The engine sounded just like it should, and I turned it off right after getting it on the ramps.

I really do hope that this does the trick....
 
#23 ·
Hi,

A little tip / trick that I use when they are real tight / corroded in ......................

They are going in the bin anyway, so cut / snap the sensor top off very close to the hexagon, then use a decent 6 point socket with a decent breaker bar, avoids the chances of rounding them off, and all the subsequent work that can be involved when that happens :wink

If you have room and a long enough 6 point deep socket, cut the wires and use that ;)

Also applies to old pipework unions etc :wink

HTH,
 
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#24 ·
Once I confirm the replacement sensor is correct, I ALWAYS cut the wire and use a socket. If there is room for one. My second choice is a box end wrench if there is room. A buddy of mine had a tool that fit in his air hammer. Pretty slick. I tried finding one on Amazon with negative results. Next time I see him I will try to remember and ask.
 
#25 ·
I see your point, guys. Since this was my first run around this course, I figured, better extract them intact, just in case. I did get them out. But I'll remember those tricks for those really rusted-in ones.

The 2003 S430's O2 sensors also got done this evening. Yep, all four of 'em. Those were pretty easy. I'll take it for a test drive tomorrow when it's light out.

Question: is it a good idea to reset the engine learning information in SDS after replacing O2/Lambda sensors? Or is it not necessary? Honda Civics don't need it, but this ain't no Honda; dis be Da Benz, so I want to make sure.
 
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#26 ·
Hi @cowboyt,

I do, it is the "proper" way to do the job ...................

It should theoretically re-learn given time and mileage, but can take ages if the adaptives are jacked to end of scale, a reset kick starts the whole process from middle base line and so the Car seems much better from the get go :grin

Same with Transmission work like conductor plates, solenoids, rebuilds etc :wink

HTH,
 
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