AlexMercedes

That's really upsetting that AMG will stop making V12s...

There is nothing wrong about the engine itself, its pretty bulletproof. It's just everything around it and attached to it that always fails, and the cost of keeping it running because of those faults tend to create the illusion that the engine is unreliable. Main culprits being the ignition system and suspension. I love this powertrain, I've driven many cars and nothing compares to it, but it definitely has faults. Hopefully all of those faults were eliminated in the new models, which seems to be the case so far. Looking forward to getting an M279 in a few years.

Welwynnick

All cars have their faults.

It just happens that the weaknesses on the M275 are frustrating but relatively benign and manageable.

Owners of other up-market cars curse them just as much as we do, if not more.

Nick

tusabes

AlexMercedes

The biodegradable harness during that era affected all cars, not just the M120, so its not an engine-specific problem like coil packs are to a m275. It would be a nightmare if that weren't the case. Imagine every Mercedes from the early 2000s had the same ignition system....

I actually recall having a dream where my W140 S500 had the same stupid coil packs and it was the most disturbing thing ever. Glad I woke up from that. Lol

But yes overall its good to see that these issues finally have been addressed, its just sad to see how it took them 2 generations to sort the ignition issue, especially when they sorted the 90s wiring harness issue only within the same generation. Despite all the TTV12s isues, I would still take it over the M120 because of its power advantage and nicer sound.

AMG Lover, KRK

Speaking about ignition and maybe little bit off the main topic, spark plugs, I have replaced all the SP and coilpack but still unfortunately I get misfiring at almost redline on 2nd gear.

Is the spark plugs, when I buy it from mercedes, come with the correct gapping or do I need to gap them into certain measurement?

tusabes

MooksM275

If you are using the OEM iridium then they should be gapped correctly and are not supposed to be gapped due to the danger of damaging the irididium tip.

There are obviously various reasons that you could be experiencing this so check vacuum lines and fuel pressure first (easy stuff). I know there was one case posted here on the forum where a guy with an sl65 had a weak valve spring that caused a misfire that no one could fix. But that is rare so I suggest you start with easy stuff first.

MooksM275

I would say that if your coilpacks only lasted that long that there is some other issue. Are you sure they had that many miles? Did you change the ignition transformer? Were the spark pugs new? Did you replace all of the red insulators?
Large gap on old spark plugs is harder on the coil packs as is an old ignition transformer. Cracks in the red insulators causes spark jumping between insulator and will damage the coil packs. This is one piece on WIS that I follow every time: Mercedes procedure is to replace all red insulators every time you remove a coilpack.

As for how long m275 are running, there are plenty of examples of high mileage cars. There is a member here on the board that has a cl65 that went 225k miles. He had a stuck injector that caused issues at that point.

For reference, just checked pricing on the m279 coilpacks and they are $200 a piece and there are 6 on each side. So $1200 for one side. I know that there is a benefit that if one fails you just change one but they are not cheap and they only fit the m279/m277 so I do not expect super cheap aftermarket parts here.

LynnBilodeau

Just tried finding v12tt coil packs on the fcp euro website, and does not look like they carry them any longer.
Hope I am wrong.

exhaustgases

So lets see some good wiring schematics of the ignition system. Does it have a pulse amplifier, or sometimes called igniter? Voltage transformer so that will only work with ac or pulsating dc, so what is its function for the ignition system? Note: a coil is a transformer. I'd like to help figure out the problem.

AlexMercedes

There is a M275 training document that goes into great detail about the ignition system. Maybe it will be a great source to figure this problem out.

http://fotifixes.com/M275-initial-training.pdf

AMG Lover, KRK

Guys anyone out there knows the correct size I have to buy?

The link to ebay item is not working

exhaustgases

It does look like a very fun mess. This place does have some videos of what is inside the coil pack units. http://www.v12icpack.com/

I also read that there are still normal knock sensors just for 275 engine.It is a system that maintains the spark discharge at the spark plug for a certain amount of time, unlike old normal spark ignition systems that fire once. It is like many electronic things, it looks like a good idea until it breaks.
I'm still going to spend some study time on this. Any kind of change in the system will mean changing the power supply and the ignition modules.
I wish we had a training pdf on the M113 system to compare.
It would really be nice to see the pin outs for the connectors for all those components and description of their functions, that is what is needed the most.

I did some editing to my first post of this because I took more time studying. I thought there was a combustion knock feed back but that is only for the 137 engine.

ItalianJoe1

So you guys are really gonna spend 3k to avoid spending 2k? I don't see the point here. The replacement coils should be a one-time thing. I know it's not the best system, but don't re-invent the wheel, it works well when the parts are in good working order, just install a pair of new coils and drive the car for another 15 years. Going through all the work needed to re-wire, move things around, coding, programming, sensor trickery, just to replace 3 parts with 12? Seems backwards.

exhaustgases

I agree with you, because the only easy way to accomplish this would be to go to a mega squirt system, for most folks that is not worth it. For the non tech type sending the modules to that one outfit for repair would be the best cost effective route. Or get some after market parts if they are still available. Even to run with a stand alone controller, (which an automatic transmission would also need if the engine had one), there is still the issue of what to use to reach the spark plugs, you could use some after market coils then, you would lose tons of other functionality of the car by pretty much disabling the CAN system.

ItalianJoe1

MS doesn't have the strength needed to run this engine and interface with the rest of the car. If you take the M/E off the CAN, you might as well throw the car in the garbage, nothing works anymore.

Speeddriven did it with a Syvecs 12 standalone, but the ECU alone is 10k, not mentioning the harness and obviously custom tuning/install you will need. It allows factory level functionality with full control, but that's not the goal here. This is people that really can't afford to drive a V12 Benz because of the maintenance costs, dreaming about fixing it for $100 when something breaks. Sadly, that's not the way it goes with this platform. Pay to play in the extreme.

AlexMercedes

It's not about having enough money to afford maintaining a V12 mercedes or not. If the conversion is possible you are still paying the same amount as fixing the original system.

It just makes more sense to have a more sensible system that is much easier to maintain and much less of a PITA when working with it. Misfires will no longer be an issue because one misfire will not ruin the entire rest of the system, which happens to be this system's major weakness. It is annoying for one misfire to go and take down the rest of the system with it, almost like a kamikaze. Dealing with them individually in the affected areas rather than having to deal with other areas that are not affected at all will save a lot of time and money after such a conversion is complete.

However, knowing how complicated these cars are, it is going to be difficult for such a conversion process. And if it proves to be much more expensive and much more of a headache than just simply dealing with its poorly designed ignition system from the factory, then obviously its not worth it.

ItalianJoe1

No, the system as it is works the same. One misfire doesn't take down the system, it means you have to replace the whole coil. Do it, and drive the car for another 15 years without worry. I spent maybe $3k lets say on my ignition system, two coils, transformer and 24 spark plugs. Now, I don't worry about it one bit. The car is a 2003 with 80k miles on it when I got it, if I put another 15 years or 80k miles on this setup and had to replace it again, I still wouldn't be salty about it. Not worth the hassle to re-configure the entire system at all, even for the exact same money, which it won't be. Plus, how much is your time worth? I can install plugs/coils/transformer in about 3 hours taking my time, and i'm done. No playing with making things fit, no shipping rebuilds back and forth, no wondering if it's gonna last more than 6 months because of the used parts. My time is too valuable to waste on things like that, and if you told me right now to get in the car and drive it 500 miles, I would without hesitation. That alone keeps me from wanting to play games with it. The stock system is over-complicated and excessive, yes, but it works and is better than any reasonable alternative that I've ever seen.

exhaustgases

All this you said, I said already didn't you read what I said? With a controller it is not a strength issue, it is "will it work on a V12" that is all that is to worry about. And I said you would lose all functionality of the car. I agreed just live with the crappy expensive system they put on it. The time to worry is when the parts are no longer available. But then all wealthy MB owners will say get rid of it then.

ItalianJoe1

I provided more relevant information to expand on your thought. Go somewhere else with that "didn't you read" garbage.

ChristianRGR

It can be done, at work we do it all the time. We build Porsche 934s 935s and 962s. We also work in Indycars, F1 Cars, any racecar you can imagine. A lot of these engines have no road-car variants, and obviously there are no parts available for these engines, where you are going to find a coil for a Porsche 3.5 F1 V12, in cases like that we just look up the specs, measure our area and just get one that will work, we do the wiring and that's it. We replace ECU's, dyno tune the engines etc... quite regularly. At the end of the day an engine is just that, an engine they all work the same way.

We have used coils from GM cars in 1200hp+ Porsche Flat-6 Engines, F1 engines like superbike coils and so on. I've been evaluating this as I'd like to get a CL65 sometime in the future, I like making stuff for the cars I own and as an Engineer I like solving issues.

Also nothing wrong in wanting to make a car more reliable, that just makes it more enjoyable!

tusabes

For $999 each side you can buy lifetime warranty coils from v12icpack.com
this is really a non issue apart from cheap skates buying used $150k cars for $5000 and not having $3000 left over for eventual repairs

ChristianRGR

Is there some kind of honor in spending money that you could save or in not improving something that could be improved?

Even if the coils could be had at a good price, the problem remains, having to take all of them just to fix one IS A PROBLEM, them failing often compared to "regular" vehicles IS A PROBLEM. This is not about who has money and who hasn't, this is a matter of improving something that could use some improvement and that's it.

I hope that what I said can help whoever is interested in fixing this issue once and for all, if any of you are around the Indianapolis area, I'd love to help out, since is something that I will definitely work on whenever I get my hands on a V12 Merc.

tusabes

It would be great if someone could improve it , but really the issue is blown out of proportion because people who buy $5000 cars can’t afford $2000-3000 repairs . Then they curse the car

The original owners who paid $150k can easily afford such a repair and understand those kinds of repair bills are common on $150k cars . these cars might be $5000 now but they still have the repair costs of a $150k car.

ChristianRGR

I understand what you mean, it happens to every depreciated high-end vehicle. Many people want the ride, comfort, etc.. of a 100k+vehicle but expect the running costs of a 15k car and that is just not how it works. I think V12 Mercs are fantastic cars and to me, the coil problem is not something that dooms the car, even if there were no way around the issue I'll still buy the car. It is not that big of an issue just and annoying one that I think would be neat to solve.