When you click on links to various merchants on this site and make a purchase, this can result in this site earning a commission. Affiliate programs and affiliations include, but are not limited to, the eBay Partner Network.
Is there any easy way to diagnose whether it's the coil pack , or voltage transformer , that's the problem ? Or is trial and error of trying and changing both parts the only way ?
as I have not really big electronic scills, it's more like trial and error
but there is a little base that if you have only 1 to 5 cylinders failing on a pack, it is mostly NOT the transformer
transformer fails the whole one side or both entirely
and don't forget, that if you have been swapping coils on a pack trice, error on cylinder is still present, even with new spark plugs, that you should swap the fuel injector.
cause can be
coilpack electronics
coil
spark plug
or
injector
I am going to buy new coilpacks next, but not the mercedes benz version
But it was a great challenge again to acomplish this. some of you might just want to try the adventure too or don't have the money to buy them. have fun !
this coilpack was ALL dead. I found the two C3074 7 mosfets in the corner and investigated them. when I unsolder them one side came off. probably corrosion.
replaced both, swapped some coils, replaced all wiring between coils and coilpack with a new test version, applied some Loctite Blue 112639 against future vibrations and bingo !
You mention you are not going to buy the Mercedes ignition coils again. Which ones are you replacing it with?
It seems "easy" to replace with individual coil pack design like the M279 but how do we figure out the ionic current detection section.
I have no idea of what " ionic current detection section" is
I hate electronics, I solder like retard, but I like challenges.
I did all this with a swap and try method
the last coilpack took me 4 tries
someone with some electronic skill could fix this in minutes
you can even imagine giving info to your local electronic repair store and if you tell him where to look he would fix it in minutes too
I will replace the coilpacks with the
UNITED MOTOR PRODUCTS COP278 COP279
or
AIRTEX/WELLS 5C1219 5C1218
this just because I have a 714 HP build now and it asks much from the ignition
the Mercedes Benz coilpacks are CRAP old version AND new version, both crap
I am a internet search animal and have been reading so much about these packs that I can open a Coil-pack church.
I have no idea of what " ionic current detection section" is
I hate electronics, I solder like retard, but I like challenges.
I did all this with a swap and try method
the last coilpack took me 4 tries
I will replace the coilpack with the
UNITED MOTOR PRODUCTS COP278 COP279
or
AIRTEX/WELLS 5C1219 5C1218
the Mercedes Benz coilpacks are CRAP old version AND new version, both crap
I am a internet search animal and have been reading so much about these packs that I can open a Coil-pack church.
aha, I see!
These coil packs report misfiring events back to the ecu, unlike on other cars, where its is sensed in the cam/crank comparison via the ECU.
In the UK we only have one company that sells aftermarket coil packs, and its nearly the same prices as the dealer! £980 vs £1080
You say the new version MB ones are bad, based on what? I agree it's a silly design, as when one tiny part fails you are required to buy an entire pack, which isn't cheap. The updated packs rarely fail though, and I assure you they are all built by Temic, until someone shows proof of otherwise, be they MB or outside brand. MB does not produce the coils themselves.
The Ionic function is essentially an emissions control thing but it functions at different points for different reasons. In simple terms, it fires one of the coils a second time, and looks at the resistance it took to fire, then calculates backwards to get the cyl airmass composition using other known variables, to decide how complete the burn is in the cyl. From there it adjusts dwell to help improve it.
I believe, based on my limited understanding of the system, that this is part of the failure mechanism. When the plugs are worn, it falsely increases the resistance. This forces the coil pack to increase dwell, which gives hotter spark but puts more load on the mosfet and coil, but may not be necessary. This is why old plugs contribute to dead coils, as does tuning. People commonly blame a tune for killing coils, in reality you are asking it to do more, and electronics that have never been run that hot before don't always take well to it. I'm sure thats what helped kill my second coil pack (I broke a coil on the first one), as it has new correct plugs in it and lasted about 8 months after being tuned. It was an original pack from 2003 though, so it had run it's course IMO.
You say the new version MB ones are bad, based on what? I agree it's a silly design, as when one tiny part fails you are required to buy an entire pack, which isn't cheap. The updated packs rarely fail though, and I assure you they are all built by Temic, until someone shows proof of otherwise, be they MB or outside brand. MB does not produce the coils themselves.
The Ionic function is essentially an emissions control thing but it functions at different points for different reasons. In simple terms, it fires one of the coils a second time, and looks at the resistance it took to fire, then calculates backwards to get the cyl airmass composition using other known variables, to decide how complete the burn is in the cyl. From there it adjusts dwell to help improve it.
I believe, based on my limited understanding of the system, that this is part of the failure mechanism. When the plugs are worn, it falsely increases the resistance. This forces the coil pack to increase dwell, which gives hotter spark but puts more load on the mosfet and coil, but may not be necessary. This is why old plugs contribute to dead coils, as does tuning. People commonly blame a tune for killing coils, in reality you are asking it to do more, and electronics that have never been run that hot before don't always take well to it. I'm sure thats what helped kill my second coil pack (I broke a coil on the first one), as it has new correct plugs in it and lasted about 8 months after being tuned. It was an original pack from 2003 though, so it had run it's course IMO.
You are right, I forgot to mention
The MB benz coilpacks new version is the same crap as the old version, nothing really changed exept the silicone the close them with. based on the fact that old version presented corrosion sometimes
Just relabeled stuff
The coilpack by
UNITED MOTOR PRODUCTS
or
AIRTEX/WELLS
have better build coils at least
and yes, you are right, If you do not touch your engine, no tune, you change your sparks as supposed to, MB coilpacks are fine
anyway, if you do not touch this M275 engine, your service correctly, you will probably reach a million of kilometers before you break the engine
one last thing
I based the conclusion that OEM Temic coilpacks are crap mainly on reading
Tons of people complaining that they bought new coilpacks from MB and having problems again
Nearly, or none complaint buying other non MB coilpacks and having problems after that
Question: I previously have had random misfires, but it'd go away after shutting down the engine. Well, last month as I was approaching a stop light I got (what I believe to be) a complete failure of one of the coilpacks. When I start up the car, it definitely has an odd sound, and CEL turns up right away. When I scan the codes, it comes up as 300, 301, 302, 304, 305, and I don't remember if I saw 303 and 306 in there.
Does this sound like a coil pack failure? While I'd like to do the mods noted in this thread to save money, I unfortunately just don't have the time. I originally was going to buy MB coils, but now I see that RockAuto also sells a different brand that may *potentially* be better? Which part number (both RockAuto and MB) is the 1-6 side?
Rock auto and all other sellers sell the exact same coil pack as oem , Theres only one manufacturer and they are reboxed by different suppliers
if you can find a vendor with a lifetime warranty like autozone or oreilly who will price match that's even better
Note it may be your voltage transformer rather than the coil pack . V12icpack.com rents out both the voltage transformer and coil packs to troubleshoot
I checked with a new scanner today, and it's all six cylinders 1-6. I guess I will start with a new voltage transformer @ $750 and hope that's the fix. If not, on to the coil pack...
First of all, millions of thanks to pmercury for this thread and all of the pioneering "open source" work on this. This thread has been a great help for me diagnosing the problems with my M275 engine, but now I don't know what to do next...
It started with the CEL. I pulled the codes, random misfires on passenger side. Erased the codes, and it was fine for one 10km run. Then on the way back, CEL again, now a code of random misfires and couple of cylinders misfiring on the passenger side. Put the car in a heated garage for a week as it had been cold and moist outside for some time, figured that might help it. Erased the fault codes and again, was fine for a 10km run, then when I fired it up, CEL again. And just a note, this far there had been no judders or anything from the engine, the only way you would know there were misfires, was the CEL. OK, so with encouragement from this thread, I ordered a set of 24 NGK spark plugs, the OEM type, as well as 24 BERU insulators.
I got the parts, installed them this weekend, and made a note that the passenger side coilpack seemed to be the only original part with manufacturing year before the car's, whereas the transformer and passenger side coilpack were 4-6 years younger than the car. The passenger side coilpack seemed OK other than seeming to have some oxidation in the springs, which I took off and cleaned with brake cleaner and a bit of brushing on both "conductive ends" to make sure the electricity flows there. I assembled everything with putting a little bit of silicone grease on the insides of the BERU insulators (which touches the spark plug porcelain), and a bit more on the outside, which sits against the coil's metal tube.
I fired it up, no CEL, no judders, no nothing. Checked engine smoothness with STAR, all other cylinders 0 faults except cylinder 4 a couple of faults occasionally, mostly showing 0 as well. Drove about 10km to a garage to work on other stuff. Then fired her up, got a juddery start and CEL. Read the codes, random misfires on the passenger side and misfire codes for all 6 cylinders on the passenger side. Erased the fault codes, rinse repeat, judders on the idle, gets smoother on some rpm ~1500.
Now I am a little lost what next.
If the voltage transformer was the root cause, would it have been running smooth for a while right after putting it back together? Logic would tell me there would have been no smooth running at all.
If the passenger side coil pack was the root cause, it would be quite rare for all cylinders to fail, right?
If the silicone grease or the way I put it back together otherwise was the cause, I would certainly be getting trouble on the driver's side too?
Could it be any of the sensors mentioned here? Do they cause this kind of symptoms?
Any help would be greatly appreciated. I do have screenshots of the faults with STAR, but need to get to my other computer to post those.
First of all, millions of thanks to pmercury for this thread and all of the pioneering "open source" work on this. This thread has been a great help for me diagnosing the problems with my M275 engine, but now I don't know what to do next...
It started with the CEL. I pulled the codes, random misfires on passenger side. Erased the codes, and it was fine for one 10km run. Then on the way back, CEL again, now a code of random misfires and couple of cylinders misfiring on the passenger side. Put the car in a heated garage for a week as it had been cold and moist outside for some time, figured that might help it. Erased the fault codes and again, was fine for a 10km run, then when I fired it up, CEL again. And just a note, this far there had been no judders or anything from the engine, the only way you would know there were misfires, was the CEL. OK, so with encouragement from this thread, I ordered a set of 24 NGK spark plugs, the OEM type, as well as 24 BERU insulators.
I got the parts, installed them this weekend, and made a note that the passenger side coilpack seemed to be the only original part with manufacturing year before the car's, whereas the transformer and passenger side coilpack were 4-6 years younger than the car. The passenger side coilpack seemed OK other than seeming to have some oxidation in the springs, which I took off and cleaned with brake cleaner and a bit of brushing on both "conductive ends" to make sure the electricity flows there. I assembled everything with putting a little bit of silicone grease on the insides of the BERU insulators (which touches the spark plug porcelain), and a bit more on the outside, which sits against the coil's metal tube.
I fired it up, no CEL, no judders, no nothing. Checked engine smoothness with STAR, all other cylinders 0 faults except cylinder 4 a couple of faults occasionally, mostly showing 0 as well. Drove about 10km to a garage to work on other stuff. Then fired her up, got a juddery start and CEL. Read the codes, random misfires on the passenger side and misfire codes for all 6 cylinders on the passenger side. Erased the fault codes, rinse repeat, judders on the idle, gets smoother on some rpm ~1500.
Now I am a little lost what next.
If the voltage transformer was the root cause, would it have been running smooth for a while right after putting it back together? Logic would tell me there would have been no smooth running at all.
If the passenger side coil pack was the root cause, it would be quite rare for all cylinders to fail, right?
If the silicone grease or the way I put it back together otherwise was the cause, I would certainly be getting trouble on the driver's side too?
Could it be any of the sensors mentioned here? Do they cause this kind of symptoms?
Any help would be greatly appreciated. I do have screenshots of the faults with STAR, but need to get to my other computer to post those.
a bad voltage transformer usually kills an entire side of the engine , so you'll get either a 1-6 misfire or 7-12 misfire , not just one or two cylinders
a bad voltage transformer usually kills an entire side of the engine , so you'll get either a 1-6 misfire or 7-12 misfire , not just one or two cylinders
Thanks tusabes. That's what's baffling me, that as the fault codes now show misfires on all cylinders 1-6, could the voltage transformer have died on me right after replacing all the spark plugs, after being completely fine for the first 10km following the spark plug replacement? The fact that the voltage transformer has been replaced at some point, as well as the fact that it was fine for 10km, kinda would point me to another direction? Or could the voltage transformer really experience a sudden death following a spark plug change and a short drive of working just fine?
My issue rang up as an occasional single cylinder misfire. Then one day the whole bank died suddenly, but just needed a restart and all was cured. Over the course of a year I'd get a few misfires here and there, and towards the end the entire coil pack had misfires on all 6 cylinders; happened pretty abruptly. Ended up changing the coil pack (it was not the voltage transformer).
07-15-2017, 03:18 AM
![m[][0etpor-sove's Avatar](data:image/svg+xml;utf8,<svg xmlns='http://www.w3.org/2000/svg' viewBox='0 0 50 50'><circle class='avatar-circle-default' fill='%237bd276' cx='25px' cy='25px' r='20px'></circle><text class='avatar-text-default' x='49%' y='53%' fill='white' text-anchor='middle' alignment-baseline='middle'>m</text></svg>)
