M278 Oil in wiring harness
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M278 Oil in wiring harness
I have a 2012 E550 with M278 engine. My mechanic found oil in the wiring harness and He tried to clean it multiple times but still couldn't resolve the problem. He told me I need to replace the wiring harness. How much is the wiring harness? What about the labor cost?
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2011 E550 Coupe
I suggest cleaning the harness and correcting the leak so it stops happening. There's no sense replacing the harness just to let it fill up again. You should be able to spray Brakleen through the same route the oil took. Keep in mind that oil is not conductive, so it shouldn't matter that electrical contacts get oily. I even use dielectric grease on spark plug boots. I have seen spark plug wells full of oil with no effects.
Last edited by oldmots; Apr 16, 2022 at 08:39 AM.
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From: unbegrenzt
2017 GLE350 4MATIC
Hundreds of posts on this on the site.
Offenders are cam position sensors and cam magnets.
Victims are ECU, O2 sensors, injectors and coils.
If caught early enough, new cam sensors and magnets, plus a thorough cleaning will solve it.
If not caught early enough, a new ECU and other victim parts need replaced, plus the engine harness. This is solvable, but the cost and effort to do so depends on how far the problem has developed.
Offenders are cam position sensors and cam magnets.
Victims are ECU, O2 sensors, injectors and coils.
If caught early enough, new cam sensors and magnets, plus a thorough cleaning will solve it.
If not caught early enough, a new ECU and other victim parts need replaced, plus the engine harness. This is solvable, but the cost and effort to do so depends on how far the problem has developed.
Out Of Control!!
Joined: Sep 2018
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From: unbegrenzt
2017 GLE350 4MATIC
M274, M276, M278 and M157 engines.
M274 seems least affected based on posts on this site.
Used on:
W212 and W213 E-Class
W205, maybe W204 but not sure C-Class
166 all variants
X204 GLK
X253 GLC
W222 S-Class
Time frame is the two thousand teens.
M274 seems least affected based on posts on this site.
Used on:
W212 and W213 E-Class
W205, maybe W204 but not sure C-Class
166 all variants
X204 GLK
X253 GLC
W222 S-Class
Time frame is the two thousand teens.
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From: Houston Metro
16 Acura RDX 128k mi 2013 MB E550 4M 124mi
Oil in wiring harness
I have a 2013 E550 4M (in the shop now) - they found oil in my wiring harness after I asked them to replace my Camshaft Position Sensors (4) and my Camshaft Solenoids (4)
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Out Of Control!!
Joined: Sep 2018
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From: unbegrenzt
2017 GLE350 4MATIC
No, any vehicle with the above referenced engines can be affected by oil in the harness. I am not aware of each and every platform where MB used these engines, I listed the ones I am aware of. The list is not exhaustive but rather representative.
The M274/276/278/157 are from the same generation and have a large collection of commodity bits and pieces shared among them. For example, cam position sensors.
The M274/276/278/157 are from the same generation and have a large collection of commodity bits and pieces shared among them. For example, cam position sensors.
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From: Orlando, FL
2016 E400 Coupe (C207)
Does anyone know why the campaign ends with 2011, e.g., did subsequent model years use revised parts to avoid this?
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10-second E550
Member
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From: Nashville, TN
'18 E400 Cab
Check your engine type and many other OEM details by putting your VIN in this site. https://www.datamb.com/ My 2016 Cabriolet is the M276. I believe you'll have the same engine.
Super Member
Joined: Sep 2017
Posts: 738
Likes: 163
From: Orlando, FL
2016 E400 Coupe (C207)
Check your engine type and many other OEM details by putting your VIN in this site. https://www.datamb.com/ My 2016 Cabriolet is the M276. I believe you'll have the same engine.
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Joined: Mar 2020
Posts: 43
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From: Houston Metro
16 Acura RDX 128k mi 2013 MB E550 4M 124mi
Mr Toad
I was told my 2013 is not covered even though the symptoms are similar - found oil in CPS not Cam Solenoids (magnets) - ECU is backordered - ETA ???
I was told my 2013 is not covered even though the symptoms are similar - found oil in CPS not Cam Solenoids (magnets) - ECU is backordered - ETA ???
