Ignition Coil do it yourself repair
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m[][0etpor-sove (10-03-2017)
#2
IMPORTANT ! if you buy new coils for your coil-pack, buy MOTORKING ONLY
these are superior build, supposed never have to be replaced again
ALSO, YOU MUST HAVE MERCEDES XENTRY DAS (live Fault Counter) to precisely see what coils fail ! or any advanced code reader that has a live fault counter
PART 1
======================
Opening the sealed cover
First of all, I am pretty sure that the best method is to heat up the whole coil at 100 degrees celcius / 212 farenheit in a oven (this is how you remove the glass from your headlights)
I don't have a big oven like that so:
So here is my method for now
with heatgun, heat up the borders for around 20cm, then cut the whole border of
do this 20cm by 20cm
once that done all around, heat up again and cut the silicone all around
the the difficult part, the silicone around the plug
3 of the 4 sides around the silicone plug are easy, space enough to insert a hot screwdriver and push the silicone
one side is impossible to insert a screwdriver
solution is to drill a small hole on one side to be able to insert the screwdriver
result
PART 2
======================
THE FAMOUS OIL IN COIL LEAK
So, when removing your coil pack you will probably find oil in the last, passenger & driver side coil.
Why ? it's just the two cylinder head gaskets
change them !, preventive too ! because these leaks can kill your coilpacks
A1370160221
A1370160321
Rubber gasket had no breaks, but was hard cooked
PART 2bis
======================
sometimes your problem is just these sensors, not your pack
also, if you have one side failing only, swap the camshaft position sensors left with right
and see if your problem changed
if not, they are OK
verify they gaskets and clean them up
PART 3
============================
sometimes your problem is just these spark plugs, not your pack
before testing, if you don't know how old they are or they have mileage or look old
replace all your spark plugs !
THE ONLY RECOMMENDED PLUGS ARE:
NGK 5648 / IFR6Q-G
laser iridium
PART 4
==============================
sometimes your problem is just this transformer , not your pack
Problem could also be your transformer
easy to open don't worry
verify the device like here
PART 5
====================
sometimes your problem is just these spark insulator caps, not your pack
If you go for a repair with old coilpacks
you might want to reuse the old red spark insulator caps
I went for a superior upgrade
24 x BERU GS30
OEM part is
A0001590080
PART 6
===================
The mosfets replacement, don't forget to use thermal compound and cover the with epoxy once finished
sorry, green dots a bit small but just download the picture and zoom in
only GREEN and RED mosfets are provided in repair kits. maybe because those fail most of the time
additional info, it's confirmed, the UR4120 mostly NEVER fail. so you probably never need to replace these.
Products you need for mosfet replacement :
MOSFETS DATASHEETS:
EDIT 2020
this is more than 3 years old, I am much more advanced now and I would also check there capacitors, same way as on the voltage converter
these are superior build, supposed never have to be replaced again
ALSO, YOU MUST HAVE MERCEDES XENTRY DAS (live Fault Counter) to precisely see what coils fail ! or any advanced code reader that has a live fault counter
PART 1
======================
Opening the sealed cover
First of all, I am pretty sure that the best method is to heat up the whole coil at 100 degrees celcius / 212 farenheit in a oven (this is how you remove the glass from your headlights)
I don't have a big oven like that so:
So here is my method for now
with heatgun, heat up the borders for around 20cm, then cut the whole border of
do this 20cm by 20cm
once that done all around, heat up again and cut the silicone all around
the the difficult part, the silicone around the plug
3 of the 4 sides around the silicone plug are easy, space enough to insert a hot screwdriver and push the silicone
one side is impossible to insert a screwdriver
solution is to drill a small hole on one side to be able to insert the screwdriver
result
PART 2
======================
THE FAMOUS OIL IN COIL LEAK
So, when removing your coil pack you will probably find oil in the last, passenger & driver side coil.
Why ? it's just the two cylinder head gaskets
change them !, preventive too ! because these leaks can kill your coilpacks
A1370160221
A1370160321
Rubber gasket had no breaks, but was hard cooked
PART 2bis
======================
sometimes your problem is just these sensors, not your pack
also, if you have one side failing only, swap the camshaft position sensors left with right
and see if your problem changed
if not, they are OK
verify they gaskets and clean them up
PART 3
============================
sometimes your problem is just these spark plugs, not your pack
before testing, if you don't know how old they are or they have mileage or look old
replace all your spark plugs !
THE ONLY RECOMMENDED PLUGS ARE:
NGK 5648 / IFR6Q-G
laser iridium
PART 4
==============================
sometimes your problem is just this transformer , not your pack
Problem could also be your transformer
easy to open don't worry
verify the device like here
PART 5
====================
sometimes your problem is just these spark insulator caps, not your pack
If you go for a repair with old coilpacks
you might want to reuse the old red spark insulator caps
I went for a superior upgrade
24 x BERU GS30
OEM part is
A0001590080
PART 6
===================
The mosfets replacement, don't forget to use thermal compound and cover the with epoxy once finished
sorry, green dots a bit small but just download the picture and zoom in
only GREEN and RED mosfets are provided in repair kits. maybe because those fail most of the time
additional info, it's confirmed, the UR4120 mostly NEVER fail. so you probably never need to replace these.
Products you need for mosfet replacement :
MOSFETS DATASHEETS:
EDIT 2020
this is more than 3 years old, I am much more advanced now and I would also check there capacitors, same way as on the voltage converter
Last edited by pmercury; 07-01-2020 at 07:00 AM.
#3
for this adventure, I just got 2 packs from same car L & R
left has 4 coils failing, right only 1
price 500$
don't forget that if 1 cylinder fails, not both coils have a problem
so I potentially have 19 working coils and two working modules for that price
If you replace cover gaskets also, why not replace you engine wiring
MB recommends to change these as the heat dries them up after 8 years
make sure you get latest model A2751501833
I found a close to new one
ebay is full of them
more tips further in this post
left has 4 coils failing, right only 1
price 500$
don't forget that if 1 cylinder fails, not both coils have a problem
so I potentially have 19 working coils and two working modules for that price
If you replace cover gaskets also, why not replace you engine wiring
MB recommends to change these as the heat dries them up after 8 years
make sure you get latest model A2751501833
I found a close to new one
ebay is full of them
more tips further in this post
Last edited by pmercury; 07-02-2017 at 06:42 PM.
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AMG_Cls55 (02-26-2018)
#5
MBWorld Fanatic!
Interesting. I just swapped out my left side coil. I have two complete coils and the igniter I need to sell now, one has a broken coil (damaged during removal), and the other side started to develop misfires on the rear 3 cyls and had codes for a Cyl #10 A/B coil fault.
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2MERKS (07-10-2022)
#7
Interesting. I just swapped out my left side coil. I have two complete coils and the igniter I need to sell now, one has a broken coil (damaged during removal), and the other side started to develop misfires on the rear 3 cyls and had codes for a Cyl #10 A/B coil fault.
I have been doing some soldering over years, my experience is that I don't want to touch Iphones and ECU chips anymore
this I don't touch
this I do solder
so seriously, did you see the size of the soldering on the coils and eventually the mosfets ???
Even a blind could solder that !
So that added to the mystery created that there is nobody explaining you how to open these packs ...... weird !
only warnings like, you can fix it yourself but don't !
this is why, ladies and gentleman, I am doing it... I didn't say I will succeed, but probably
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#10
Member
#12
Actually, I do touch those. Nearly every day, since I'm the Renesas applications engineer for those very parts. But even I, with more than 35 years experience as an electronics and software engineer, would not expect to successfully repair the circuit boards on these coil packs without a schematic and parts data sheets.
You are going to need some high-end soldering and de-soldering equipment to replace those MOSFETs without damaging the PCB. Not only that, there are numerous (very tiny) associated components, such as MOSFET driver ICs, flyback diodes, etc. around them that could also be faulty.
Good luck, you'll need it.
You are going to need some high-end soldering and de-soldering equipment to replace those MOSFETs without damaging the PCB. Not only that, there are numerous (very tiny) associated components, such as MOSFET driver ICs, flyback diodes, etc. around them that could also be faulty.
Good luck, you'll need it.
that is preventive
and that, even a donkey can solder
#14
Member
So how do you know whether a coil itself is bad, or whether it is the driver circuitry? Do you have a testing strategy, or will you just shoot the parts cannon at it and hope on blind luck that you accidentally succeed?
#16
First of all, if you don't have Xentry Das, forget about it (just added that to the threat start, thx !)
I will be only switching coils and eventually those two mosfets according to DAS
if the board fails, then I can choose between a local electro repair store or discard it
Last edited by pmercury; 06-26-2017 at 01:57 PM.
The following users liked this post:
pmercury (06-26-2017)
#18
Just a suggestion: You can test the coil windings for open or short using a multimeter to check resistance. Infinite = open, 0 ( or close) = shorted. Something in between = maybe good. Measure a known good coil for comparison. Check the primary winding at the 3 terminals where it connects to the driver circuit. This should be relatively low resistance. Check the secondary between the spark plug spring terminal and the shell ground. Resistance should be relatively higher. Might save some money by not replacing a coil that may actually be good.
here is a link to two pictures so you can download them, add comments and post it here
http://imgur.com/a/Xcoi3
thx for your help
#21
thank you sir.