michiganw203

I brought my 09 e350 into the dealership to get my brakes replaced. I've had a mild vibration at idle that I've been noticing for about 1.5 years (after I had the mounts replaced). The RPM's never changed during it, never stalled, and never drove any different. I mentioned this to the dealer, and they told me that they found some oil by the ECU (supposedly from leaking magnets wicking oil up). The car had the updated retrofitted adapters installed in 2012 (before I owned it). The tech cleaned out the oil that he could see but they suggested that I replace the wiring harness (for $5,000 along with 4 magnets). Would this be causing the vibration? I occasionally get misfire codes P0302 (0652) and p0300 (0632). I've replaced all spark plugs and the coil pack for the misfiring cylinder. Electronics aren't my specialty, but I just don't see how oil in the wiring harness would be causing this. I also found the timing of it unusual (since I have not been to the dealer in about 1.5 years and haven't really had any problems since I've owned the car). How fast does contamination typically occur, and how long do we typically expect to see the vehicle last if the problem is not resolved?
Finally, I was told that some vehicles are very easy to change the harness, whereas others require some significant disassembly. Anyone know for a 2009 e350 how involved this is? I'd prefer not getting rid of the car, but I'd also prefer not spending thousands on poor product design.

chassis

Misfiring and rough running happens when the harness is saturated with oil and oil insulates contact pins causing intermittent loss of connection, which the ECU doesn't like and CEL and rough running are the result.

Harness saturation takes time. CEL and misfire can happen early in the saturation process, or later, without warning.

The root cause is leaking cam position sensors and cam magnets. The permanent corrective action is to replace those parts. If the harness has been saturated, a new harness is required. If the ECU has been affected, either cleaning the ECU connector or a new ECU may be required.

Most of the time, if caught early enough, replacing the sensors and magnets is sufficient.

How long will the vehicle last? Unknowable. It sounds like you have codes, CEL and rough running now. I wouldn't put up with that, and would either repair it or dump the car.

Dealers are out to hose you, plain and simple. Take it to an independent repair shop and get another estimate, it will likely be half of the dealer's attempted hose job.

michiganw203

Thanks for the reply @chassis !
I honestly don't feel like dumping a ton of work and/or money into a car this old; however, I don't really want to buy a new one either. I generally prefer to drive my cars for as long as possible and have only owned this for three years.
Theoretically, if I were to replace all magnets and cam sensors (which is what the dealer said were leaking) and then periodically clean the harness ports to the ECU and/or any visible oil, could I potentially extend this? My thinking is that if I stop the leaks and then routinely clean any wicking oil, I could maybe avoid having to deal with it so immediately?
This is somewhat of a separate question but I haven't been able to find any similar threads. The dealer told me that the car had the retrofitted adapters installed in 2012 to avoid this problem. Therefore it seems that one, some, or all of those adapters failed. I don't presume MB would consider covering any of this given that their preventative campaign failed (the dealer I spoke with said they would not).

chassis

Yes, this is a viable option. People have reported on this site that new sensors and magnets (plus new spark plugs, ignition coils and O2 sensors) make a world of difference in engine power and smoothness. Checking for and cleaning wicking oil from the saturated harness would be necessary if the harness is not replaced. I would start with weekly checks, then move to monthly, but no less frequent than monthly imo.

No one knows for certain if the pigtails on your car were installed prior to leaks, and if the pigtails are a long term reliable solution. MB came out with the pigtails then changed sensor and magnet design several times. So nothing is certain about this, except for MB's design failure. One of many on the garbage heap of MB design botches.

michiganw203

Thank you again! @chassis I'm driving back home (to Michigan) next week, so once I get there, I'll change the sensors and magnets and then just periodically clean the wicking oil. I also have a trusted mechanic in Michigan so I'll see what he quotes on actually replacing the harness.

Also, for anyone interested, I reached out to MBUSA regarding the campaign for the retro fit (Campaign No. 2012070002). I noticed that the most recent updates (from 2012) say "inclusion of primary loss damage" and "inclusion of consequential damage." I asked them if this meant that MB should be responsible for "consequential damage." The representative I spoke with found the campaign and said it is a possibility and that management would be reaching out to me in the next day or two. I don't have my hopes up, but I'll keep you updated in case of good news for anyone else dealing with this!

michiganw203

[QUOTE=chassis;8686943]Yes, this is a viable option. People have reported on this site that new sensors and magnets (plus new spark plugs, ignition coils and O2 sensors) make a world of difference in engine power and smoothness. Checking for and cleaning wicking oil from the saturated harness would be necessary if the harness is not replaced. I would start with weekly checks, then move to monthly, but no less frequent than monthly imo.

Also I'll look into 02 sensors. I recently did the plugs and one coil pack (the cylinder that was throwing a code). Didn't make much of a difference (likely because the oil was the problem).

chassis

Good choice to replace sensors and magnets. Also consider changing the ignition coils if they have not already been changed.

Please keep us updated on the outcome with MB corporate.

Mojo20032004

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thtguy

sorry posted to an old thread by accident.