W221 misfire
07-23-2024, 05:33 PM
#1
Newbie
Thread Starter
W221 misfire
Greetings all dear members,
I have a w221 s350 2006, first it was misfiring, I changed the plugs switched the coils and it didn't work, then I went to another shop, who suggested that I change the battery. I did and it didn't work. Then someone told me that it's pressure is not good. I suspected that was not a correct answe as the misfire would go somtimes when I switch off then on, I checked with another shop they said pressure is fine but it's an ecu problem, I chnged the ecu and it misfired then on the new ecu I changed one misfiring coil and magically it worked like a bee, then later I said to my self I should change all coils and plugs, so I bought kella and boschwhen I installed the new stuff it misfired again. Then later on the misfire was on two cylinders, I went to the shop, changed the ecu the misfire disappeared for a short time, to reappear shortly, he said it's the MAF, he disconnected it and I tried it it was shaking but not misfiring, he plug it again and it didn't misfire until next day, it sarted to misfire again.. I think I said misfire like a 100 times, but it's really driving me crazy, if you can help me I would relly appreciate it
I have a w221 s350 2006, first it was misfiring, I changed the plugs switched the coils and it didn't work, then I went to another shop, who suggested that I change the battery. I did and it didn't work. Then someone told me that it's pressure is not good. I suspected that was not a correct answe as the misfire would go somtimes when I switch off then on, I checked with another shop they said pressure is fine but it's an ecu problem, I chnged the ecu and it misfired then on the new ecu I changed one misfiring coil and magically it worked like a bee, then later I said to my self I should change all coils and plugs, so I bought kella and boschwhen I installed the new stuff it misfired again. Then later on the misfire was on two cylinders, I went to the shop, changed the ecu the misfire disappeared for a short time, to reappear shortly, he said it's the MAF, he disconnected it and I tried it it was shaking but not misfiring, he plug it again and it didn't misfire until next day, it sarted to misfire again.. I think I said misfire like a 100 times, but it's really driving me crazy, if you can help me I would relly appreciate it
07-23-2024, 06:06 PM
#2
sounds unbelievable - but some guy with a strange misfire a few months back spent loads replacing nearly everything - trying to resolve a random misfire coming and going - eventually some specialist at a third garage claimed to have resolved with a secret squirrel ECU reset of adaptions - but not the ones u see and can get at with dealer tools !!!
other than finding that bit of secret magic - try and replace the CPS $60 and die all the time
other than finding that bit of secret magic - try and replace the CPS $60 and die all the time
07-23-2024, 06:44 PM
#3
MBWorld Fanatic!
Greetings all dear members,
I have a w221 s350 2006, first it was misfiring, I changed the plugs switched the coils and it didn't work, then I went to another shop, who suggested that I change the battery. I did and it didn't work. Then someone told me that its pressure is not good. I suspected that was not a correct answe as the misfire would go somtimes when I switch off then on, I checked with another shop they said pressure is fine but it's an ecu problem, I chnged the ecu and it misfired then on the new ecu I changed one misfiring coil and magically it worked like a bee, then later I said to my self I should change all coils and plugs, so I bought kella and boschwhen I installed the new stuff it misfired again. Then later on the misfire was on two cylinders, I went to the shop, changed the ecu the misfire disappeared for a short time, to reappear shortly, he said it's the MAF, he disconnected it and I tried it it was shaking but not misfiring, he plug it again and it didn't misfire until next day, it sarted to misfire again.. I think I said misfire like a 100 times, but it's really driving me crazy, if you can help me I would relly appreciate it
I have a w221 s350 2006, first it was misfiring, I changed the plugs switched the coils and it didn't work, then I went to another shop, who suggested that I change the battery. I did and it didn't work. Then someone told me that its pressure is not good. I suspected that was not a correct answe as the misfire would go somtimes when I switch off then on, I checked with another shop they said pressure is fine but it's an ecu problem, I chnged the ecu and it misfired then on the new ecu I changed one misfiring coil and magically it worked like a bee, then later I said to my self I should change all coils and plugs, so I bought kella and boschwhen I installed the new stuff it misfired again. Then later on the misfire was on two cylinders, I went to the shop, changed the ecu the misfire disappeared for a short time, to reappear shortly, he said it's the MAF, he disconnected it and I tried it it was shaking but not misfiring, he plug it again and it didn't misfire until next day, it sarted to misfire again.. I think I said misfire like a 100 times, but it's really driving me crazy, if you can help me I would relly appreciate it
07-23-2024, 09:19 PM
#4
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2007 S600, 2007 Chrysler 300 SRT8, 2000 C5 Corvette, and 2017 Mustang GT, and just got a 2023 300C
This does sound like a fuel pump issue to me. Of course, as my spouse often reminds me, WTF do I know?
You did not specify mileage but with it being a 2006; I would swap out that fuel pump.
You did not specify mileage but with it being a 2006; I would swap out that fuel pump.
07-24-2024, 02:43 AM
#5
thinking over night
I think the secret reset - is to hold key in cranking position for 10 seconds (or was it 30 seconds) and it turns of a fake Merc software fault...
sounds highly likely with the way these crooks do software
when the garage said pressure was low - low pressure of what ? cyl compression quite likely - low fuel pressure I have never noticed on this forum until its flavour of the week (this week)
I think the secret reset - is to hold key in cranking position for 10 seconds (or was it 30 seconds) and it turns of a fake Merc software fault...
sounds highly likely with the way these crooks do software
when the garage said pressure was low - low pressure of what ? cyl compression quite likely - low fuel pressure I have never noticed on this forum until its flavour of the week (this week)
07-24-2024, 10:24 AM
#6
Newbie
Thread Starter
sounds unbelievable - but some guy with a strange misfire a few months back spent loads replacing nearly everything - trying to resolve a random misfire coming and going - eventually some specialist at a third garage claimed to have resolved with a secret squirrel ECU reset of adaptions - but not the ones u see and can get at with dealer tools !!!
other than finding that bit of secret magic - try and replace the CPS $60 and die all the time
other than finding that bit of secret magic - try and replace the CPS $60 and die all the time
07-24-2024, 10:24 AM
#7
tried it yet ? - there's a number of later Mercs where they got caught being naughty and the ambient temp readings where part a fake EML light - they had to "update" the engine ecu software to cure it
I'm away so can't try - but I just remembered shortly before my car went mad and started drinking fuel at 25% more than it ever did in the 8 years prior (just as it has with a mate and his 2009 CL500) - one day my ambient temp sensor went mad and started counting down as I was driving !!!!!!! then went normal and never ever did it again
I'm away so can't try - but I just remembered shortly before my car went mad and started drinking fuel at 25% more than it ever did in the 8 years prior (just as it has with a mate and his 2009 CL500) - one day my ambient temp sensor went mad and started counting down as I was driving !!!!!!! then went normal and never ever did it again
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07-24-2024, 10:27 AM
#8
Newbie
Thread Starter
it's with one cylinder number 1 the fuel pressure I didn't check as from the nature of the misfire I suspected it to be some kind of an electric problem, when ai first changed the ecu it had more misfires the car was shaking more, so I returned and bought another one and then it was stable on this one cylinder misfire
07-24-2024, 10:49 AM
#9
Newbie
Thread Starter
thank you for the advice I didn't check this, how can I check without spending a fortune?
07-24-2024, 10:51 AM
#10
Newbie
Thread Starter
thinking over night
I think the secret reset - is to hold key in cranking position for 10 seconds (or was it 30 seconds) and it turns of a fake Merc software fault...
sounds highly likely with the way these crooks do software
when the garage said pressure was low - low pressure of what ? cyl compression quite likely - low fuel pressure I have never noticed on this forum until its flavour of the week (this week)
I think the secret reset - is to hold key in cranking position for 10 seconds (or was it 30 seconds) and it turns of a fake Merc software fault...
sounds highly likely with the way these crooks do software
when the garage said pressure was low - low pressure of what ? cyl compression quite likely - low fuel pressure I have never noticed on this forum until its flavour of the week (this week)
Last edited by Mercedes guy 1; 07-24-2024 at 10:57 AM.
07-24-2024, 10:52 AM
#11
Newbie
Thread Starter
thinking over night
I think the secret reset - is to hold key in cranking position for 10 seconds (or was it 30 seconds) and it turns of a fake Merc software fault...
sounds highly likely with the way these crooks do software
when the garage said pressure was low - low pressure of what ? cyl compression quite likely - low fuel pressure I have never noticed on this forum until its flavour of the week (this week)
I think the secret reset - is to hold key in cranking position for 10 seconds (or was it 30 seconds) and it turns of a fake Merc software fault...
sounds highly likely with the way these crooks do software
when the garage said pressure was low - low pressure of what ? cyl compression quite likely - low fuel pressure I have never noticed on this forum until its flavour of the week (this week)
07-24-2024, 12:02 PM
#12
it would have to start ...I guess - but keep holding the key - the way Merc wire it, they crank till it fires - proposed method, I think will stop cranking (once started) but send a signal telling the car to stop misbehaving as secret Merc fix is in play
would be interesting to hear if it helps !
would be interesting to hear if it helps !
07-24-2024, 12:15 PM
#13
Newbie
Thread Starter
it would have to start ...I guess - but keep holding the key - the way Merc wire it, they crank till it fires - proposed method, I think will stop cranking (once started) but send a signal telling the car to stop misbehaving as secret Merc fix is in play
would be interesting to hear if it helps !
would be interesting to hear if it helps !
07-24-2024, 02:02 PM
#14
...I think the idea is holding in a position you never do for 10 seconds is what triggers it - of course they other guy could be talking silly - this is the same trick as fixing the battery light on the facelift ones....
07-25-2024, 03:00 PM
#17
well you have the fully monty of detritus to work through there
obviously it should report back NO faults at all - I wonder if your cheap gadget can clear stuff ?
you may be stuck with records of old lies and rubbish from ages back - certain issues can vanish if its not been throwing teddies for 3 key on / off cycles and this makes dash warning lights go out - but what stays listed as bugs its once had can be rather more interesting to get rid of
I have one gadget that somehow finds a list of shadow faults (a secret list of garbage I guess meant to help Merc as dev tool using customers cars) - you can clear the list they like you to know about and this one stays listing it - it seems if I go in certain modules and go into the non std enabled developer mode of dealer tools, I can delete these - but even then its not a consistent solution.... its particularly irritating if a module gets flashed with an update and it takes down canbus circuits - these can throw every faults merc invented on that canbus and they don't like to go away.
anyway that's likely far more issues listed than are currently real - but cheap tools tend to lie and make up faults - wipe them all out and probably use a better tool after a short drive - on phone apps scanmaster is one of the less useless phone apps - and the paid one able to clear, yet is still super cheap - I can use on my 221 just for engine stuff it works very well
the blocked CATs and the mass air flow are a worry - the misfire ones could be from when the coil sticks played up - you should NEVER drive with a misfire as it damages stuff - whilst the car knows a cyl is out, they leave the petrol pouring in to break the car on purpose, when they could easily turn of the injector for that cyl but they don't bother !!!
https://play.google.com/store/apps/d...anmaster&hl=en
.
obviously it should report back NO faults at all - I wonder if your cheap gadget can clear stuff ?
you may be stuck with records of old lies and rubbish from ages back - certain issues can vanish if its not been throwing teddies for 3 key on / off cycles and this makes dash warning lights go out - but what stays listed as bugs its once had can be rather more interesting to get rid of
I have one gadget that somehow finds a list of shadow faults (a secret list of garbage I guess meant to help Merc as dev tool using customers cars) - you can clear the list they like you to know about and this one stays listing it - it seems if I go in certain modules and go into the non std enabled developer mode of dealer tools, I can delete these - but even then its not a consistent solution.... its particularly irritating if a module gets flashed with an update and it takes down canbus circuits - these can throw every faults merc invented on that canbus and they don't like to go away.
anyway that's likely far more issues listed than are currently real - but cheap tools tend to lie and make up faults - wipe them all out and probably use a better tool after a short drive - on phone apps scanmaster is one of the less useless phone apps - and the paid one able to clear, yet is still super cheap - I can use on my 221 just for engine stuff it works very well
the blocked CATs and the mass air flow are a worry - the misfire ones could be from when the coil sticks played up - you should NEVER drive with a misfire as it damages stuff - whilst the car knows a cyl is out, they leave the petrol pouring in to break the car on purpose, when they could easily turn of the injector for that cyl but they don't bother !!!
https://play.google.com/store/apps/d...anmaster&hl=en
.
Last edited by BOTUS; 07-25-2024 at 03:16 PM.
The following users liked this post:
Mercedes guy 1 (07-25-2024)
07-27-2024, 09:42 AM
#18
Newbie
Thread Starter
well you have the fully monty of detritus to work through there
obviously it should report back NO faults at all - I wonder if your cheap gadget can clear stuff ?
you may be stuck with records of old lies and rubbish from ages back - certain issues can vanish if its not been throwing teddies for 3 key on / off cycles and this makes dash warning lights go out - but what stays listed as bugs its once had can be rather more interesting to get rid of
I have one gadget that somehow finds a list of shadow faults (a secret list of garbage I guess meant to help Merc as dev tool using customers cars) - you can clear the list they like you to know about and this one stays listing it - it seems if I go in certain modules and go into the non std enabled developer mode of dealer tools, I can delete these - but even then its not a consistent solution.... its particularly irritating if a module gets flashed with an update and it takes down canbus circuits - these can throw every faults merc invented on that canbus and they don't like to go away.
anyway that's likely far more issues listed than are currently real - but cheap tools tend to lie and make up faults - wipe them all out and probably use a better tool after a short drive - on phone apps scanmaster is one of the less useless phone apps - and the paid one able to clear, yet is still super cheap - I can use on my 221 just for engine stuff it works very well
the blocked CATs and the mass air flow are a worry - the misfire ones could be from when the coil sticks played up - you should NEVER drive with a misfire as it damages stuff - whilst the car knows a cyl is out, they leave the petrol pouring in to break the car on purpose, when they could easily turn of the injector for that cyl but they don't bother !!!
https://play.google.com/store/apps/d...anmaster&hl=en
.
obviously it should report back NO faults at all - I wonder if your cheap gadget can clear stuff ?
you may be stuck with records of old lies and rubbish from ages back - certain issues can vanish if its not been throwing teddies for 3 key on / off cycles and this makes dash warning lights go out - but what stays listed as bugs its once had can be rather more interesting to get rid of
I have one gadget that somehow finds a list of shadow faults (a secret list of garbage I guess meant to help Merc as dev tool using customers cars) - you can clear the list they like you to know about and this one stays listing it - it seems if I go in certain modules and go into the non std enabled developer mode of dealer tools, I can delete these - but even then its not a consistent solution.... its particularly irritating if a module gets flashed with an update and it takes down canbus circuits - these can throw every faults merc invented on that canbus and they don't like to go away.
anyway that's likely far more issues listed than are currently real - but cheap tools tend to lie and make up faults - wipe them all out and probably use a better tool after a short drive - on phone apps scanmaster is one of the less useless phone apps - and the paid one able to clear, yet is still super cheap - I can use on my 221 just for engine stuff it works very well
the blocked CATs and the mass air flow are a worry - the misfire ones could be from when the coil sticks played up - you should NEVER drive with a misfire as it damages stuff - whilst the car knows a cyl is out, they leave the petrol pouring in to break the car on purpose, when they could easily turn of the injector for that cyl but they don't bother !!!
https://play.google.com/store/apps/d...anmaster&hl=en
.
should the battery voltage be swinging between 13.4 and 14?
Last edited by Mercedes guy 1; 07-27-2024 at 09:53 AM.
07-27-2024, 11:57 AM
#19
P0301 is cyl 1 misfire (front right when sat in the car....)
F
R 1 2 3
O
N 4 5 6
T
wiring or coil stick - coil sticks die on german vehicles every other journey !!!
of course could be mechanical (valves, piston or head gasket) - but coil stick is the likely one
F
R 1 2 3
O
N 4 5 6
T
wiring or coil stick - coil sticks die on german vehicles every other journey !!!
of course could be mechanical (valves, piston or head gasket) - but coil stick is the likely one
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Mercedes guy 1 (07-29-2024)
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