testknight

So I have a 2008 R350 with the P0016 and P0017 codes coming up. I'll start by saying the car seems to drive and run fine. I only discovered the code as I was prepping the car for sale and wanted to be sure there was nothing new aside from a known thermostat code I never really dealt with. The only new codes were P0016 and P0017 outside of that known thermostat one. I did clear the codes and both came back when I checked after one drive cycle.

So my confusion comes in after I checked for cam alignment. I set the crank to needed 305 degrees and pulled all cam sensors save the outside one on the driver's side (that one seemed to be a bit more of a pain to get to and I figured 3 would be enough to evaluate anyway). So, on the two inside sensor holes (I think those on the intake cams) the stamped circle was, I'd say, dead center. The outside one on the passenger side was hard to tell. It could have been very slightly off or centered, but I was having a harder time getting a visual angle on it. If it was of center, it would have just been a millimeter or two. The stamped image was fully visible and inside the cam hole and closer to the center than to either edge. It didn't look near as off as any video or image I saw indicating misalignment.

I'm just hoping someone might have some thoughts on all this...really trying to determine if I just need to accept I still need that big cam alignment job that sounds like costs as much as the car is worth or if it could be an easier fix of swapping out all sensors and selenoids/magnets (I don't want to spend the money if it isn't going to work):

- Anyone ever heard of one that might have been just a hair off center? AS mentioned the two inner sensors were lined up and this one out seems it might have just been a hair off. Again it was hard to tell it was even off-center, but if say it was just a couple millimeters off, would that be ok or no?

- Does the fact that the codes came back right away tell us more on it definitely being that super expensive alignment issue? I'm not sure if a sensor issue if it would be incremental or come back immediately like this one did

- Anyone ever heard of someone having his issue and finding that just swapping the sensors and/or solenoids/magnets to address the issues/codes? .Does that ever even happen? Seem optimisitic to me, but am nor reading much other than vague references that it could fix the issue so wanted to see if that worked for anyone here.

- if only sensor or selenoid/magnet issue (and I'm not holding my breath that's all it is)...should I replace all sensors and solenoids? Just the sensors?

I'm sure these are dumb questions. I'm just a bit frozen at what to do next at this point. Am I screwed to that $4k+ job, just need to replace sensors and/or solenoids..or perhaps are there other things I should know about this that I didn't pick up in previous research. I do appreciate any thoughts on this from anyone who may have been through it all already.

cetialpha5

If you read the old threads, the standard thing that most do is replace the sensors, both sets and to get the Mercedes parts, not aftermarket. Both sets of sensors/magnets aren't that cheap though. FCPeuro seems to think Bosch and VNE are OE so maybe those might be ok.

chassis

What is the history prior to pulling the sensors? Did you remove, replace or adjust the camshafts?

testknight

Hey, thanks for your responses.

chassis - No nothing really prior to codes, but then I'm really not sure how long they were there as I always assumed it was a thermostat code that I never really worried about and the car ran just fine. The only issue I did have late last year (I don't drive the car much and just use it for a short drive to work and back during winter only as my daily driver hates cold weather) was just after I had just changed oil on the car. I went to the store to realize I must not have firmed the oil filter housing as apparently oil got all over and thus caused the belt to slip off. I limped the car home, having to stop twice due to heat (due to the belt not staying on for the water pump). I buttoned that all up next day and all seemed to drive fine after. It was stupid...I've done an easy 50 oil changes on Benzes and was really disappointed in myself on that one.

cetialpha5 - ok, I must have used targeted words in my searches as I didn't land on much of anything where the fix was just the sensors. I am trying that next..see below for another 'data point' that got me to just go ahead and try it.

Since my post I found this video...this guy described the same thing I did,...on his, he checked all four sensor hole/ports and one of them was just a hair off like mine. He was indicating there that he wasn't worried about it and all looked good to him. He just replaced sensors too. The video is in spanish so I had to turn on closed captioning, then manually entered text near the end into a translator.

Needless to say, I just purchased four new sensors and then also just picked up 4 magnets/selenoids as well for $200 all in. I really wanted to avoid dropping a couple of hundred bucks if it wouldn't fix the issue, but I decided it was well worth trying it as the other method is a huge expense...so to me the math started to work. If I'm wrong, fine. Needless to say once I get this all in within next week or two, I'll be sure to come back here and report results. Hopefully it helps someone in the future.

Here is video:

chassis

Thanks for the reply. I don't understand the notion that the camshafts may be off timing. Why would that be the case? How could the cams get off-timed, in your mind?

testknight

Hey Chassis,

My search on the codes, and you likely know this, but just clarifying, (P0016 and P0017) all lead me to do that visual check of alignment by setting crank to 305 degrees and visually verifying if the stamped image on cam ends lined up dead center to the ports (see early part of the video below). If not dead center, then it was that huge cam adjustment process described later in the same video.

What initially threw me off and made me unsure was that the one port didn't line quite dead center. As mentioned it was very close, but not perfect, so I posted here in hopes someone had the same experience and could tell me if it being slightly off with the same codes still needed to do that larger repair described in the latter part of the video below or if just sensors fixed the codes from appearing.

It sounds like this was more of an issue on the '06-'07 model years. That said, I could be using the wrong terminology here somewhere and am cool if corrected on any of it. Here is the video that summarizes where my research all landed me surrounding P0016 and P0017 codes in terms of diagnostics and repair (when things indicate misalignment).,

testknight

As a follow up on this. I did replace all sensors and solenoids/magnets. As mentioned when I took a look at my cam alignment (see video) by setting crank to 305 degrees and then pulling the two passenger side cam sensors, I saw one that was perfectly lined up and another that was just a tad off. For anyone looking for a data point on this, in my case replacing all sensors and solenoids did not fix the issue/code (no issues detected, just the code, though I believe something will happen as a result eventually). I cleared codes and after a single drivee cycle they came right back on. I wish I didn't spend the $200 myself, but am unsure if it could work for others or not.

The repair on this looks quite expensive so I'll probably just sell it as is. I will, of course, let folks know what is going on. It stinks as the thing drives perfectly right now, but knowing these codes are in there, I couldn't sell it to some family without letting them know there is an expensive fix in its future. A younger me would consider buying a used engine and dropping it in, then repair this engine while out of car and easier to fix, then just selling that engine. I'm done swapping engines on cars though.

chassis

@testknight Why is the cam not in the correct position? What is the root cause of this?

testknight

@chassis I really can't say for sure, but if I had to guess, perhaps a stretched timing chain or wear on the cam sprockets (thus jumped a sprocket). On this topic, a guess from me isn't something I'd take to the bank though.