Clearly, if someone came up with a true plug and play fix that cost less than, say, $2000, a lot of guys would be on board.

Problem is R&D. And, who wants to be the guinea pig? I don't. While it MAY be possible to convert to 24 individual coils and a different ignition transformer, it would likely involve a huge investment in time and money to make it right, and to do it without butchering the wire harness. Lets face it, when the V12TT is running correctly, it is spectacular. I am driving an SL55 right now. Bought it just to make sure I wanted to live with the R230 body before dropping more $$$ on an SL65. Pretty sure I will sell the SL55 and purchase an SL65 next spring or summer.

When one coil pack goes out, I will buy another. Same with the other side and the transformer. If, by then someone has developed an alternative that will cost less, I would consider it, but only if it has been in use for a while and proved to be trouble free. I don't mind working on the V12TT cars; in fact, tinkering with cars is what I do for a hobby.

BTW, I went on the website v12icpack.com and didn't see anything about a lifetime warranty on coil packs or transformers. Did I just miss it?

 

Clark doesn’t advertise it , as his $699 rebuilt coils dont usually experience a warranty return . But for those who want the security of a lifetime warranty he will do it for $999. He’s a one man shop , contact him when you need one and he will help you out

 

I bought both my coil packs from Clark with a lifetime warranty for 2k. I believe I was the first customer!

I still have misfires at idle on cylinders 8,9,10 but I doubt that's because of the coils or plugs. No misfires at all during driving, especially at WOT like before. Still trying to chase it down after replacing everything.

Anyways, that still shouldn't turn people away from a coil conversion project. Yes I know its easier to just pay 2k and never worry about it again in your life, but it would still be really cool to see a conversion done just for the sake of it. At that point its not just about saving money, but instead seeing what we really could do with these cars and improve upon the design, also while making it much more serviceable and reliable for the future.

 

if you ever figure this out, or need a coil pack to experiment on i'm very happy to help. would love to see an improved coil pack.
the best, harv

 

• Everyone who is interested in the MB V12 coil packs MUST WATCH the video on the V12icpack.com site. The faulty coil pack issue is caused by MBZ faulty material specification and design of the OEM coils, The iron core in the coils corrodes and damages the thin insulation on the primary windings causing shorts and often damaging the solid state 'switches' that emulate mechanical ignition points. V12 icpack researched and developed a much better mechanical design that will not corrode and damage the coil windings and fry the solid state parts.

 

How do you know your coils need replacement? Sorry if this old mail, but this website is hard to follow

jeff. 11/15/2019

 

You’ll have a misfire and the check engine light will come on , a scan tool will show codes 300-312

 

The dual objectives of high specific power and low exhaust emissions are not congruent. The emissions laws require the 'normal operation' combustion to be extremely thorough and at moderate temperature to avoid NOx formation. High specific power output needs a richer mixture and hotter combustion temperature. Very precise control of fuel:air ratio is necessary to avoid 'partial combustion' events where the intense power stroke flame goes out in some areas. This 'partial misfire' results in many times more unburned hydrocarbons than normal and could overheat and damage the emissions control catalysts. The 'oxygen sensor' is much to slow to respond to these 'partial misfire' events. The usual method of 'misfire detection' uses the angular acceleration of the engine flywheel during each power stroke to sense the reduced power output. That will not work for a 'partial misfire' situation. Research has found that the residual 'ionization potential' remaining can be sensed through the spark plugs/ignition coil using additional circuitry. (General Motors DELCO Division has been the major developer of combustion and emissions control) Unfortunately, this additional circuitry (which is also used by Infiniti) is not as robust as 'normal' coils. When that sensing circuitry does not work properly, a 'misfire error' is triggered.

It is questionable whether deleting this 'partial misfire' detection system is legal under the current law.

 

Any system designed to monitor exhaust emissions usually can't be tampered with legally. If it's disabling could result in an increase in tailpipe emissions I would bet it's against the law.

 

The 'new high tech' ignition systems generate a 25KHz spark event (at 30KV) , the duration of which is controlled to maintain the spark for a set crankshaft rotation (20 deg?)
The 'old fashioned' coil/condenser system generated a resonate oscillating spark lasting several cycles (multiple spark strikes) but not duration controlled. It was what it was depending on the capacitance/inductance/resistance values. It WAS NOT a 'single spark,', but was uncontrolled.
These new systems measure the 'ionic conduction' by imposing a 1KV electrical signal to the spark gap and measures the current passage.vs time. The electrical conductivity relates to the combustion process. A 'normal' combustion has initially high conductivity,that decays predictably after the sparking event, then rises again as the burning progresses and increases combustion chamber pressure and temperature. Incomplete combustion (misfire) does not have the second increase in conductivity, 'Knocking' generates a series of sharp increases/decreases caused by the pressure oscillations of the 'knocking.' The engine control module detects these rapid pressure oscillations (knocking) just like conventional 'knock sensors' would, though now EACH cylinder knocking can be measured and adjusted appropriately. The 'old model V-12's in the early-late '90's also monitored each cylinder with conventional knock sensors AND crankshaft position sensors so the ignition timing of each cylinder was adjusted EACH ignition cycle to keep that cylinder at 'trace knock'. Misfires were detected by deviations in angular acceleration of the flywheel--misfire had no or reduced angular acceleration.
I cannot fathom WHY Mercedes abandoned a very very good and 'never failed' ignition management system for the fragile and unreliable system we have to deal with.

 

How is the system of these coilpacks fragile and unreliable, exactly? My 2004 SL600 went 15 years and 88,000 miles before the driver side coilpack bent bust. Clark rebuilt it for about $750 and a week or two later I put it back on the engine - along with all new spark plugs and it's back running like a champion. I can imagine it should be okay for another 80K miles or ten to 15 years? Even if the other side quits tomorrow, I'd just have that side rebuilt and put it back in. For a car that cost $136,000 when new I don't think it's a bad apple. And the way it runs so well, basically unlike anything else, sure it's not a simple distributor cap, rotor and wires like you find on a W124 300E, but the car is phenomenal. It doesn't seem to me that it's particularly a bad design or especially fragile. Clark does use better technology parts in some places than original, due to upgraded technology over time. My 1991 R129 500SL had an ignition problem that took a while to figure out: Condensation built up in the driver side distributor cap and shorted out the sparking, even with new cap, new rotor, new spark plugs... I wondered for a long time, why would the car run okay for a few miles then crap out and run like junk, I'd turn around and drive it home and just wonder what to do. Finally I read somewhere about condensation inside the distributor cap, and a fix that involved putting silicone inside the cap behind an insulator, I thought this was bunk for such a car. Once that was "fixed' though, the problem never came back. But I did struggle and wonder what the problem was for the better part of a year. That car had about 325HP, my SL600 has twice that horsepower. When I first got my SL600 I read about the dreaded coilpacks and hoped I'd never fall victim; Now that one of mine did it my attitude is, "If the other breaks I know where to send it for rebuild". So, break or don't: I don't care. If it does, once rebuilt, I expect at least ten years service out of a rebuild. With the crazies out there who have nukes, I wonder if we will all even be here that long! There's nearly nothing that drives like this SL600.

 

That you have experienced reasonable service from the ignition system is wonderful. Unfortunately that is not typical and you should be sure and contribute to the almoners fund at the Masonic Lodge. I am certain the engineers that developed the engine and ignition system had their good reasons. That does not change the FACT the system is a MAJOR FLAW with the car and seriously impacts the resale value. Few 2nd or 3rd prospective buyers want to take on this risk? or certain expensive failure. It is not as bad a the 'carbon fiber brake rotors' costs, or the defective head bolt head design and wrong metallurgy on the previous version V-12's , or the dismal incorporation of 'bio-degradable wiring insulation' that plagued all the 90- through mid 90's vehicles and sent so many of the otherwise fine vehicles to 'the wreckers'. , or how about the defective A/C evaporators in all the S-class from 89-97? with a $2500+ cost to fix, or------.They continued to sell and use a defective fuel pump relay for over 20 years, it having horrible solder joints that were certain to fail. The horrendously costly water intrusion into the floor mounted SAMS, etc from a simple plugged plenum drain--that is too small for the debris than can fall in there and is not visible, not a routine service issue or mentioned anywhere?
I am not impressed with Mercedes 'field performance/ quality feedback environment.

I do like the driving experience of my 2001 s-600 and find the ABC defects easy and cheap to 'fix' permanently. Simply changing the oil and filter every 20K miles and/or switching to DEXRON VI + 10% USLD, shielding stuff from intense radiant heat, and replacing the German rubber hoses with U.S. industrial quality at a good hydraulic shop--all just like Citroen does for 60 years now--- but the ignition coils ARE a certain to happen but impossible to 'fix' expense. Horror stories abound about 10-15% of the 24 @ $30 iridium spark plugs defective from Dealer, and 'misfire' error codes when there are none caused by 'defective' spark plugs.

I am restoring my ' 94 sl-600--starting with the wiring, then the A/C evaporator, the top hydraulic cylinder seals made with the wrong material, the certain to return oil leaks (wrong seal materials again) from the front alloy joints on the V-12engine . Driving that car is intoxicating.

Once again, I AM THRILLED to hear of a GOOD IGNITION SYSTEM EXPERIENCE and congratulate you for your good luck.

 

Kebowers makes some very good points - we really shouldn't sleep on this horrible ignition design! Or any other horrible design choices as a matter of fact. Tony, I'm glad that you have had an amazing experience with your coil packs, but unfortunately you are only the minority. And I envy you.

2 rebuild coil packs and 24 brand new spark plugs later, still getting misfire codes! Ha! What a great system...

 

Impossible to fix? I've owned three V12TTs, had ignition problems with all of them, and fixed all of them myself. Not easy, but not impossible.

Every other high end car to my knowledge has big bad problems, and our coil packs, while a weak point, are the least of the ownership nightmares.

Nick

 

Too many people don't read the fault codes correctly, and blame the coil packs for the "misfire" (especially with cheap diagnostic equipment).
Misfire codes with (only with DAS readout possible) TWC DAMAGE are not caused by the coil pack, but by the ECU shutting down the cylinders affected to protect the CAT.
Learn before expensive parts swaps!

 

While we are on that topic, what do you think misfires only at idle could be from on these cars? I get very noticeable misfires at idle that rumble the car, it is really bad in the mornings when the car is cold. It gets better as it gets hot.

Under load, it performs flawlessly and never misfires. So that's telling me it can't be related to the ignition system.

I've changed all spark plugs, both coil packs, all map sensors, checked for vacuum leaks, checked pcv system, and had no luck. Cyl 8, 9, & 10 are the culprits. I don't think its a compression issue.

 

have you changed the Spark plugs and all 4 oxygen sensors ? If not it’s time

 

I suspect your misfire at cold idle is caused by two thing happening--1) an ignition coil power supply that is marginal and fuel injectors with poor spray patterns. There is so little fuel injected at idle, the time so short that ANY hesitation in the spray starting is a big deal. Same with spark cause--a weak power supply unable to feed the 25 KHZ 30 KV spark is also a critical need at idle.
BEEN THERE with a Infiniti Q45 which has very similar ignition misfire detection set-up. At first was a off spec ignition coil 'feedback' circuit, and then an 'off spec' new spark plug not giving the correct gap resistance after ignition .

That 3 adjacent cylinders are guilty asks about tiny air leak into intake manifold.

 

I doubt its the ignition system since all plugs and coils are essentially new. Problems in the ignition system will usually show up/get worse at load, but it performs flawlessly at load and at WOT (putting aside a TCC issue I'm currently trying to deal with).

My battery is 4 years old now and a bit weak, but I don't think that would cause idle misfires. I'm thinking it could indeed be under-performing fuel injectors or oxygen sensors. I haven't heard of intake manifold leaks on these cars.

 

I add Chevron Techron with a fill up to all my FI cars quarterly. Keeps injectors clean.

 

Concerning the 3 cylinder cold start idle misfires---while it acts like a weak mixture, it could also be caused by carbon/crud deposits on the intake valves. I am not familiar with the intake manifold arrangement on that engine, but I would suggest you inspect it very carefully, hunting for any possible leak or a vacuum line that could feed oil vapor in those manifold runners (and build up crud on the intake valves). An 'old school' method of searching for small intake leaks is using a propane (or butane) torch (not lit) and plastic hose to drift the propane onto every possible crevice or leak point. The old V-8's in model 126's had numerous air leak points where numerous moulded rubber pieces joined to admit idle air to the cylinders. Even liquid gasoline dribbled onto the idle air manifolds was effective at locating leaks.. Other potential causes are of course a weak spark or defective spark plugs, though 3 adjacent cylinders are unlikely to have identical failures like this. I do suggest examining the injector electrical harness to rule out a weal signal to those injectors.

That it is worse at cold idle does tend to support a weak fuel:air mixture. Swapping injector locations is a possible easy way to confirm / rule out those fuel injectors. Also check every connection onto the manifold, tracing the lines back to their other end and testing what they connect to as they might be defective and leaking air into the manifold.

Keep hunting, patiently, and keep us advised. There IS a reason for the weak firing.

 

Would you share your experience, travails, and methods for fixing the ignition problems on your TT engines? There are lessons for us there/ PLEASE PLEASE

 

It was recently colder than usual here in Los Angeles, and starting the engine on a really cold morning made the car misfire so bad it actually threw a CEL this time and the ECU shut off the offending cylinders and the car ran really rough. I had to wait for the car to warm up and restart it for the misfires to go away. Never came back when warm, although I still feel it intermittently misfire and tremble a bit at idle, but nowhere near as bad as when it is cold.

I don't know what that could be from. I recently inspected my intake valves and they looked cleaner than a brand new BMW's intake valves. Especially on cylinder 10, which is one of the problematic cylinders. I could only think of under performing injectors at this point.

I noticed every time I remove the throttle body Y pipe there is a significant amount of oil in the driver side intercooler. I wiped it clean, and when I inspected it just a few weeks later it was back to being just as oily. I know its normal for it to be a little oily because of the PCV being routed to that side, but is this much oil abnormal? Would it cause those misfires?

 

NICK !!!! Please please share with us your trials, tribulations, process, methods and solutions You developed to solve the ignition problems on you TT engines. There are very useful lessons there for us dumb wannabe's

 

I cannot see the valve tulips clearly but there are not hugh deposits for sure. I do suggest doing a good 'spray clean' with it running using 'carb or MAF cleaner and see if it improves things.

Also some of the low visc (0wXX) oils have IMHO excessive 'evaporation loss' when measured by the NOACK test. Look for Youtube videos comparing the brands. Some are over 15%, while others are under 5%. Higher evaporation loss will coat the intake system via the PVC system but will provide 'top cylinder lubricant??' They will also increase intake valve deposit issues.

Your ignition coil assembly may have a weak 'power transistor' that powers the three misbehaving cylinders. Also check the power connection wiring to the fuel injectors for any damage. Adjacent cylinder misfire indicate some common issue---small intake leak (manifold-head gasket?) vacuum line to failed actuator?, crack or porous casting in manifold? Swapping injector positions may show a faulty injector(s). SOMETHING is not right.