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It's in the harness already and made it way into the ECU. The car is running with no problems, but now it's only a matter of time. Right connector top left pin and 9th pin.
Get this swapped today guys.
It looks like a 30 minute job if I go slow. Passenger side. 1 Passenger side 2. Hidden under the intake cloth tube. Driver side 1. Nasty goop of oil on driver side closer to the center. Driver side 2, it's hidden under the intake cloth tube. (looking at it from the driver fender).
Last edited by S. Madman; May 31, 2021 at 12:30 PM.
Sorry to hear. Would you be willing to save the leaking parts (cam position sensor?) and both thoroughly clean and take a good number of clearly focused, well-lit photos? So far on this topic, site members have not definitively identified the root cause of the sensors leaking oil. One notion is that the plastic injection molded sensor body cracks over time, and because it is exposed to oil, the oil enters the sensor internals, finds its way to the connector contacts, and migrates through the harness.
Another check that can be done, is to lightly pressurize the failed sensor with air (sensor removed from engine), to see if the leak path can be found. This would need an air source (bike pump or compressor) and a way to adapt the air source to the camshaft position sensor connector, for example with a rubber tube using hose clamps on each end. Then observe a hissing sound or spray with soapy water and look for bubbles. I realize this is a bit of work. The benefit is for the MB user community to find a definitive root cause.
I initially though that it was blowing by the O ring inside the sensor, then creeping thru the side of the outside shell, then back into the harness connector (thru the rubber piece).
But then I think it could be going thru the pins.
So I blew on the connector side of the sensor to see if air went thru, and it was pretty sealed. But what if heat is causing the plastics to expand, and allow oil to creep in.
The only way to test for that is to heat gun a sensor, and then try to blow on the pins.
I still think the first scenario is the correct diagnosis.
I cleaned up everything up, and will let it run for a little to see how quickly it leaks.
I already ordered the replacement, and should be a quick job.
I'm thinking a hairline crack develops in the plastic sensor body. Air pressure to create flow or a hissing sound would need to be fairly high, more than a human can generate. If the theory is correct, over time with heat, the liquid oil wicks into the cracked sensor body, then it's game over.
Sorry to read about your sipping connectors. I know it's common knowledge around here that the ECU won't like the incoming engine oil.
Perhaps we can bullet proof the ECU a bit before it's too late... epoxy the pins of both ECU connectors on the inside.
What's the failure mode with oil contamination??? does it just isolate all contact points.. then you should loose camshaft sensors and solenoids first with DTC's, right ??
Imagine the 722.9 TCM module and half dozen of shift solenoids and shaft sensors laying in the sauce... No problemo, there's got to be a way to befriend oil 🤔
Did you see any oil swamping your intake? intake swamp results from weak PCV design
I believe the PCV is responsible for allowing crankcase PRESSURE build up instead of a VACUUM.
The internal pressure is what blows oil through connectors and engine seals, one after the other.
Last edited by CaliBenzDriver; May 31, 2021 at 06:13 PM.
Reason: inta
@CaliBenzDriver MB issued a field fix for leaking cam magnets, it's a jumper harness. I bought one to experiment with, haven't installed it yet. It has a leak-proof wire that is a distinct feature. I haven't seen the details of the transmission electronics that are exposed to oil, but they most certainly are designed to either tolerate the oil, or be impervious (sealed) against it. The engine ECU is most definitely not designed to be immersed in oil, and apparently is not tolerant of the oil as it wicks through the harness and coats the ECU pins.
@CaliBenzDriver MB issued a field fix for leaking cam magnets, it's a jumper harness. I bought one to experiment with, haven't installed it yet. It has a leak-proof wire that is a distinct feature. I haven't seen the details of the transmission electronics that are exposed to oil, but they most certainly are designed to either tolerate the oil, or be impervious (sealed) against it. The engine ECU is most definitely not designed to be immersed in oil, and apparently is not tolerant of the oil as it wicks through the harness and coats the ECU pins.
The latest cam position sensors and cam magnets don't seem to have complaints on this site (yet). There have been many part number revisions on these components in EPC.
He got PN# 271150273364
from FCPE (see post #14 above), many part distributors also make this OEM pigtail available.
The way I got it is you still need to replace the camshaft position sensors regardless of camshaft "magnets" (solenoids) wiring. Two different parts with the same oil leak x4Pcs
Last edited by CaliBenzDriver; Jun 2, 2021 at 02:18 AM.
Got all them replaced. The magnets did not leak ( but I think is because they may have gotten swapped when they changed the timing chain 3 years ago)
For the love of whichever deity you pray to, if you have a 2015 or below...CHANGE THEM NOW!!.
Every...single camshaft sensor had oil in them. The one that I showed was the worst, but all of them were starting to leak, internally.
Please spend the money to fix it (I spend $450 in parts, and a hour of labor....or go to the dealer and have it fix it for you).
If you let this go A: you are going to have to start all over again making payment on another car. B: put $12,000 to get it fix or C: spend a car lifetime cleaning the ECU (if you don't short out other components).
It would have taken me 30 minutes if I was not trying to record it (but failed because my camera decided to go to sleep).
If you are going to to this yourself, get the magnet bolts. They came with some thread locker that it's tough to get out. 12 in total.
The sensor bolts had no threadlocker so I reused them, and added blue threadlocker.
The latest cam position sensors and cam magnets don't seem to have complaints on this site (yet). There have been many part number revisions on these components in EPC.
Would you happen to have those revised numbers so we don't land on the obsolete SKU's that are defective from factory ?
Mercedes SLR McLaren 722 S Is Extremely Rare Example Modified by McLaren
Slideshow: A one-of-one U.S.-spec Mercedes-Benz SLR McLaren Roadster became even rarer after a factory-backed transformation at McLaren's headquarters.
but it looks same sensor and wiring style used
