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Ah yes, I replaced mine recently. It was challenging for sure. I got a long handle flex 1/4 ratchet that was extremely helpful in getting it off. The passenger side cat had to come off as well.
Ah yes, I replaced mine recently. It was challenging for sure. I got a long handle flex 1/4 ratchet that was extremely helpful in getting it off. The passenger side cat had to come off as well.
You can actually see the amount of oil on the connector itself. It looks like it’s towards the front, down at the bottom of the motor behind the bottom pulley.
@Sltncls63 (or someone else)
Can you show us where this senor is located? Have seen the picture by @JEC_E63S but that's not super helpful since it's a parts diagram.
Have to add that even those three pictures above seems to be from different locations?
@Sltncls63 (or someone else)
Can you show us where this senor is located? Have seen the picture by @JEC_E63S but that's not super helpful since it's a parts diagram.
Have to add that even those three pictures above seems to be from different locations?
Thank you in advance!
Better if you check it from under the car more easy you need to remove safety cover under the engine.
I replace this sensor at dealer they drop the engine to replace it no more leak now .
So these last few posts specifically pointing at a weak leak in the m157 engine that causes the cam sensors/magnets to start leaking?
No - this is a known sensor failure. The sensor(s) allow oil to penetrate through the plastic enclosure around the pins inside the connector, oil then gets wicked through the harness all the way to the CPU, and most likely there create bad contacts and numerous electrical error codes etc.
New sensors do seem (sadly) to exhibit the same behavior over time.
No - this is a known sensor failure. The sensor(s) allow oil to penetrate through the plastic enclosure around the pins inside the connector, oil then gets wicked through the harness all the way to the CPU, and most likely there create bad contacts and numerous electrical error codes etc.
New sensors do seem (sadly) to exhibit the same behavior over time.
How does oil travel upwards when gravity prevents such things? I would assume this being one of the lower sensors on the engine, that it's traveling down the wire, and not up?
How does oil travel upwards when gravity prevents such things? I would assume this being one of the lower sensors on the engine, that it's traveling down the wire, and not up?
The cam magnet and cam position sensor oil-into-harness phenomenon affects M274, M276, M278 and M157. Possibly also earlier M271, M272 and M156. But focused mainly on the first group mentioned.
The cam magnet and cam position sensor oil-into-harness phenomenon affects M274, M276, M278 and M157.
Possibly also earlier M271, M272 and M156. But focused mainly on the first group mentioned.
To the above list of oil-in-harness providers, you can add the oil pump socket plug wether a "pressure sensor" or "pressure mgt solenoid".
It's responsible for $16.000 temporary repair described in earlier posts of this thread. Noted with same failure relaps later, then out of pocket tab.
oil pump tap socket (from thread above)
leaking socket plug (from thread above)
Last edited by CaliBenzDriver; 10-28-2022 at 02:21 PM.
And does anyone know if that is a 2 prong or 3 prong plug? I'm curious if the sacrificial harness pigtails work on that sensor too like the cam magnets.
And does anyone know if that is a 2 prong or 3 prong plug? I'm curious if the sacrificial harness pigtails work on that sensor too like the cam magnets.
I don't know this answer yet but I think someone needs to develop a kit that really protects our cars. Im a hobby electronics person and it doesn't seem like a hard ask for someone with manufacturing capabilities. It would be nice to have a place in the center of the wire that could be changed out. Almost like a little cartridge like a catch can...
Looking for this part number now. My edition of the catalog is from 2020.
edited: definitely not a parts pro but it does not show under engine electrical but I think this is it if we are saying oil pump. This can be a nice starting point.
Second edit with parts search on Google
part 38
or is it this coupling housing?
part 902
it becomes difficult when the diagrams are not pictographically oriented correctly and we don’t know the farfenlanguage.
does anyone having this fixed have the invoice to share?
additionally, I have not been able to install the pcv yet due to injury but its sitting there waiting to see if it helps and what condition the original is in at 60k.
Last edited by Baltistyle; 10-28-2022 at 06:32 PM.
Would adding solder to the copper braid help at all in slowing the capillary action?
seems so
perhaps you’ve seen the same. Presented by sonnax.
this was related to coolant in transmission.
also seen dielectric grease mentioned but would not know how to monitor the sensor as it would look wet. The oil would not travel past the silicone in theory.
Last edited by Baltistyle; 10-28-2022 at 07:18 PM.
never saw that but it seemed like a good idea to try something like this ... still need to change leaking sensors and man... that would be lots of wires to add solder beads to in tight places ... is this product a piggyback that does this for you? The next question is would the solder affect the wires impedance enough to cause issue with the signal? And why didn't benz already do this with this being a known issue for so many customers and engines relatively speaking
Question is - would the oil find away between the shrink wrap and to the other side of the solder ... surely it would be harder for it to do so
The M271 motoor is certainly affected by capilliary leaks from the two cam magnet sensors front of motor.
Adding to the pain is a 2022 global shortage of new wiring harnesses - took 4.5 months to find one.
Pigtails placed between the cam sensors and the wiring harness connections (two number) cost about $200USD fitted
Designed by MBz - part No.2711502733 I believe - is the "pigtail" and as the oil volume is very small -
it just bypasses the leakage to the wiring harness and no other remedial work is required.
One outline on the fault is at https://alanlennoxmotors.com.au/cam-magnet-leak-fix/
Although USA had a campaign to recall in 2012 all affected motors at no cost - 2012070002 - 557,108 vehicles
MBz Australia/Pacific had no recall and did not notify owners that a $300Aud fix could prevent ultimate failure.
I am told warranty claims were honoured, but this fault took 15 years to immobilise my C180K.
It also accelerated damage to the cam gears and chains due to misfires.
Enquiries for technical help were not answered by dealers. No electronic expert from MBz was able to be located.
An invitation to respond sent to the MD/CEO Australia/Pacific remains unanswewed.
It would appear that a great many vehicles are on the Australian roads, ignorant of this creeping oil fault.
Although MBz recalled an "inexpensive" software glitch in other models that could cause the car to stall,
they did not deem this "far more expensive" fault to be a safety issue. My car malfunctioned in traffic.
Is the PCV easy to replace? Anyone know the part number?
Found it , looks like the passenger side cat will need to be removed in order to replace it . There's surely some benefit once the miles get up there , I would assume it's not at 100% anymore . Has anyone replaced it yet ?
I have replaced mine. Taking the passenger side cat out makes it easier to get the bottom bolt. I used a flex 1/4" ratchet to access the bolts from the top from the engine bay. You can remove and replace from the bottom.
09-15-2022, 05:19 PM
