coil replacement question

Nov 24, 2008 | 01:27 AM

d2Benz

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Posts: 406

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From: Bowie MD

2017 GLE350 4MATIC, 2009 ML350 4matic, 2005 4maticWAGON (sold), A Pre-facelift W210(sold)

coil replacement question

I've got a Misfire in cylinder 1..
I changed wires and plugs..still misfire...
Coil is next culprit.
QUESTION.. If one coil goes bad, is it necessary to change ALL 3 coils?
car is a 96 e320 with 187,300miles.
I figure, if one goes bad, the remaing 2's life might be limited...

*I've heard many change coils, but no one really specified if they change all..

thanks
cheers,

Nov 24, 2008 | 02:24 AM

ohlord

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Joined: Apr 2007

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300E a couple 1994 w124wagon E320 Wagon/,1971MGB Track/Rally, MG Midget Autocross ,2000 E320 wagon.

did you

change the plug connectors?Do that first and if no improvement swap a coil and see if the misfire moves with the coil.
This is the part that usually is the weak link in the M104 ignition system.
http://www.autohausaz.com/search/pro...ug%20Connector

did you use the proper copper plugs and not get fancy and install platinums.M104 hate plats.

Nov 24, 2008 | 12:58 PM

d2Benz

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From: Bowie MD

2017 GLE350 4MATIC, 2009 ML350 4matic, 2005 4maticWAGON (sold), A Pre-facelift W210(sold)

changed....

Plug connectors are changed.
question is... Is it necessary to replace all 3 coils OR just replace the failed one.
since all are the same age....

thanks for your response OhLord!

Nov 24, 2008 | 02:49 PM

ohlord

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Likes: 16

300E a couple 1994 w124wagon E320 Wagon/,1971MGB Track/Rally, MG Midget Autocross ,2000 E320 wagon.

Did you

swap a coil to confirm that it is not a clogged injector?
If the coil is bad just replace that one.$60 at autohausaz.com

Or find one at an mb wrecker.

Nov 24, 2008 | 09:20 PM

d2Benz

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From: Bowie MD

2017 GLE350 4MATIC, 2009 ML350 4matic, 2005 4maticWAGON (sold), A Pre-facelift W210(sold)

Yes

coil was swapped and cylinder 1 is still misfiring...
where do I go from here???

Nov 24, 2008 | 09:28 PM

ohlord

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Joined: Apr 2007

Posts: 6,171

Likes: 16

300E a couple 1994 w124wagon E320 Wagon/,1971MGB Track/Rally, MG Midget Autocross ,2000 E320 wagon.

check the connector ,check for moisture,

check the injector operation with a stethoscope,should sound like the others.So coil is not bad,fuel or spark to that one cylinder is only getting affected.
Seafoam injector in half a tank of gas will clean the injector.

Nov 24, 2008 | 09:45 PM

d2Benz

Thread Starter

Senior Member

Joined: Nov 2004

Posts: 406

Likes: 7

From: Bowie MD

2017 GLE350 4MATIC, 2009 ML350 4matic, 2005 4maticWAGON (sold), A Pre-facelift W210(sold)

OhLord!

could this be a bad piston???
Just curious???

thanks

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Nov 24, 2008 | 11:35 PM

koskesh

Member

Joined: May 2006

Posts: 197

Likes: 0

1997 E320

Answer to your question: no, it is not necessary to change all coils. it is your preference. I personally wouldn't change something that's working until it breaks unless it is a safety part.

What spark plugs did you use? on that engine you have to use copper bosch ones. Part number is somewhere on this forum.

Did you clear codes after you moved the coil then start engine and wait for new codes?

Did you change entire spark plug wires or just the connectors? if the wires are old they could leak electricity.

Last edited by koskesh; Nov 24, 2008 at 11:40 PM.

Nov 25, 2008 | 12:59 AM

#10

d2Benz

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From: Bowie MD

2017 GLE350 4MATIC, 2009 ML350 4matic, 2005 4maticWAGON (sold), A Pre-facelift W210(sold)

thanks 4 response

OhLord,
I will check the injectors and clean them as suggested. I will do the other troubleshootings too. THANKS.. I will not panic. :-)

Koskesh,
wires, conncectors and plugs were all changed.
I used the BOSCH F8DC4...nope I didn't get fancy with the plugs.
codes were cleared be4 reading again.
thanks 4 the advise not to change all 3 coils

I will do as suggested and report back. thanks for sharing your knowledge with me on this issue.

Nov 25, 2008 | 08:08 PM

#11

d2Benz

Thread Starter

Senior Member

Joined: Nov 2004

Posts: 406

Likes: 7

From: Bowie MD

2017 GLE350 4MATIC, 2009 ML350 4matic, 2005 4maticWAGON (sold), A Pre-facelift W210(sold)

yipeeee

Guys thanks for all your inputs and suggestions.
My mechanic & I decided to do everything all over......
plugs/wires/connectors/coil....I only changed the bad coil...

...and all of a sudden FULL POWER...
car seems to have a little more power...

I will do the injector cleaner as suggested by the President OhLord!

the only thing left now is to find a way to clean the clogged egr pipe/tube.

Once again THANKS...