I recently purchased a 2012 ML550 with the 278 engine. First thing I did was to change the engine oil. Then few days later I got P0016 and later p0011 error codes along with the long cranking symptom. After searching about this, I found that a common problem in these engines are the chain tensioners and check valves. I had no idea it this was done to my car, so I decided to open the covers and check it up. Guess what, someone already installed the check valves, but did not upgrade the tensioner.
I installed the revised chain tensioners, but still got the error codes. I don't have any chain rattle. Besides the longer cranking (3-4 seconds) car runs and drives very good.
Some people say to move on and change the camshaft adjusters. I was aware about that and while covers were open, I rotated the engine few times and did not see any of them jumping or clicking.

Any thoughts and comments are welcome.

 

Careful not to confuse things, adjusters, position sensors and solenoids are not the same things.

Camshaft adjusters are $$$ to change on these engines. I would go on the easy, simpler, less expensive parts first.

Have you checked your camshaft solenoids? The ones attached to the timing covers with the wires

The M276/M278 engines are known to leak oil from the camshaft solenoids into the wiring connector, and oil sometimes (given enough time) migrate towards the ECU through the harness, then $$$$ to fix. This issue is also discussed in the W212 forum ( https://mbworld.org/forums/e-class-w...ml#post8470409)

Take the connectors out, check for oil. If oil is found, please take corrective action immediately. If not, continue checking for the solenoid being damaged (I do not have a link for a video on how to test them, but I understand they are @$50). Seen the same code in an M276 (V6 sibling of yours), and the Indy changed the solenoid/position sensor (need to check the receipt) and was done with the code.

All the best,

Pricing below
https://www.fcpeuro.com/products/mer...mer-2761530028

https://www.fcpeuro.com/products/mer...des-2761560790

https://www.fcpeuro.com/products/mer...ebi-2780505100

 

After checking for oil on the magnets and sensors connectors as mentioned above, is to think about the crankshaft position sensor and/or inspecting the cylinder bores. A bad crankshaft sensor causes several starting and running related problems. Inexpensive part but a challenge to replace. Inspecting the cylinder bores requires spark plug removal and borescoping to look for cylinder wall scoring.

 

If you are willing to spend sometime testing the source of the problem (assuming no oil leaking out any sensor), you can swap the two position sensor fro the passenger side to the driver side, and see if the code message changes from bank 1 to bank to 2. If it does, it is one of the two sensors. Then, swap one back, and repeat, the failed bank in the message is the bad sensor.

If the message still refers to bank 1, you can try swapping the solenoids now, and repeat. If the message continues with bank 1, you may try @chassis suggestion with the crankshaft position sensor; otherwise, it would pointing to something more complex, ie. Adjusters.

What oil did you use?

 

Mileage?

 

Thank you for your time, guys!
No oil leaks from the sensors. I've already done switching the solenoids, but problem still stays in Bank 1, sensor A.
I will also give a try on the crankshaft sensors to see what happens. I know adjusters is an EXPENSIVE job, but I found some videos on guys doing it without removing the valve covers.
Looks like a Chinese job, but I believe it can be done if you are careful.
https://ne-np.facebook.com/MechanicM...related_videos
What do you guys think? I know video shows Bank 2, but I believe Bank 1 is even easier.
Car has about 100k miles. The oil that I put in is MOTUL 0w/40, MB 229.5 approved.

 

Do the complete diagnosis and check all connectors for oil: 4 cam magnet connectors and 4 cam position sensors. Report back.

Before tearing into the adjusters (phasers) do a compression check and borescope on bank 1. Report back.

You haven’t done anything to rule out cylinder scuffing, which is relatively well known on this engine.

 

I will do all the sensors and compression check.
But you are scaring me out What the cylinder scuffing has to do with exactly these two error codes? I have no misfires or engine rattle.
Fingers crossed.

 

Checking compression is a "do it while you're in there" job. And the M278 is becoming increasingly known for scuffing. If you can detect it early you give yourself time to think through the options.

 

Update: Checked camshaft position sensors and camshaft solenoids. They are in shape.
I honestly didn't want to check the bottom end.
Instead I followed my instinct and went to the camshaft adjuster.
Here is the offender, intake camshaft adjuster on the passenger side:

As I don't feel comfortable paying $1000 on this piece, I sent it for regeneration. We'll see what happens in a week.

 

I would not either, and even worse if more than one adjuster is damaged, i.e. 4 x @1000. Is that price of 1000 for a new adjuster? I ask because the once listed by MB parts is remanufactured (whatever that means).. See https://mbparts.mbusa.com/oem-parts/...01bC12Ni1mbGV4

Not sure if you know there is a YouTuber named Tasos who sometimes flip the pin and reuse the adjuster.
( )
I think that would only make any sense if the wear around the hole is minimal, but from your photo it is not, correct?

If the regeneration works for you, I am certain many in the Forums would love to know who you used for the work. Good luck.

 

Actually I was quoted that price by the dealer. I am sure that was for a new piece, part # 2780501647, intake Bank 1 (pass side).
Yes, I know about Tassos. But in my case I doubt if this is gonna work. Because my pin is not that bad as the plate is. Even if it works, it won't be for a long time.
I sent it to a reputable company here in Europe, which specializes in sprockets, adjusters etc. for most problematic ones on the EDM. But first I want to see their job, then I will share with you guys. Just in case.
I will also make a short video on how we've done this job WITHOUT removing the valve cover.
Fingers crossed

 

Here is the online price for M278 (2012 year), and NEW (unlike the part for the M276 )
https://mbparts.mbusa.com/oem-parts/...tor-2780501647



Fingers crossed here as well for you..

 

UPDATE on my case:
So after finding out my intake camshaft adjuster on the passenger side is bad, I decided not to buy new one, but give it a try and rebuild it (Sorry Mercedes, you won't get my 800bucks ).
Two weeks later I got it back and went to reassembly. Many people are asking if this job can be done without removing the valve cover. YES, it can be done.
You just have to be CAREFUL and put marks on the chain and both adjusters. Then if you are replacing the adjuster, you have to copy paste the marks on the new one when doing reassembly. And yes, it is a tight job, but saves you a lot of work. Procedure is the same as the "chain tensioners", just the chain tensioner solenoid valve (torx 100) has to be loosen while the chain is in tension.


So adjuster rebuild, car reassembled. I start it and ... guess what, error code is still there Same error code, same camshaft is deviating from the crankshaft.
Many people told me it's the chain stretched or a sensor. BUT if you think logical, stretched chain would probably send error codes on both camshafts and at least make some noise.
I read that few people here replaced the camshaft as the last step. Decided to go by the procedure and check my timing:

There you go, same camshaft is off It was not much, 1-2mm probably. I guess those cars are more precise than I thought. Finally valve cover had to come off
Seems like the signal plate on the camshaft is twisting due to the rattle of the adjuster. The worst part is that if you have an early production car, you still can not be sure as there is no marks to check it. Later on, Mercedes realized about that issue and placed laser markings on the camshaft and the plate.


The good part is that if you are getting a replacement camshaft from a salvage yard (like I did ), you can figure out if it's in a good shape by checking on that markings. ( Sorry Mercedes, you missed my 800 bucks again ).
Car was reassembled, engine started and error code disappeared in 5 seconds. There was not even need to be cleared with Xentry.
PROBLEM SOLVED!!!

Conclusion: If you get P0016xx or P0011xx code, it is ether one or all:
1.Chain tensioners
2.Camshaft adjuster
and if these don't solve your problem
3. Camshaft has to be replaced

Also about camshaft adjuster , I forgot to mention that I found a small company here in Europe that specializes in rebuilding and producing their own adjusters for BMW, Audi and Mercedes ( the ones that fail most). They gave me 2 year warranty and price was 1/3 of the price of a new unit. Well, we'll see how it goes...
https://mehenker.com/en/

 

Hallo!
I have GL450, 2014, engine 278.928 and have error P0016, P0016(85), P0011(77). There is MB good service, but they don't want to check first for bad camshaft ajuster. Need to engine get out and then check. This mechanic want to change all timing chajn kit whit 3 tensioner, all 15 things. Probably balance shaft need to be change. Is it normal to change all this thing first? the car is 90 000 miles. Is all chain is streched? Is Sprocked are broke or need to change? In this case i will chage all this things and in the end have to change and camshaft ajuster, whitout take the engine out. Thge price to change all this staff is not small.
What should i do?

 

There is no balance shaft in the V8 as far as I know. V6 (M272) sure, but V8?

Please others correct me if I am mistaken.

Here is a link for the M276 (V6), no balance shaft required.

https://en.wikipedia.org/wiki/Mercedes-Benz_M276_engine

and the M278 (V8) shares the same features.

Using XEntry, the mechanics should be able to tell if the chain is stretched (assuming the camshaft adjuster has not failed yet). There is field showing the angles, and tolerances allowed. Once out of tolerances, something in the timing system is damaged: chain stretched (doubtful at 90K), adjusters (likely given the history of these M276/8 engines)

 

Yeah, they always want to change everything when they don’t pay the bill. Man, you have exactly the same error codes as I had. Don’t change the timing chains, they don’t usually stretch on this mileage. There is no balanceshaft on this engine, so first change your mechanic!
Replace both chain tensioners first and the camshaft adjuster on the intake (pass side). As you can see on my pictures, this can be done even without removing the valve cover.
If this doesn’t cure the problem, then you might look at the camshaft itself.
By the way, where are you from?

 

I'm from Bulgaria. I almost get done to change everything when, this sound strart on cold i hear not every morning, but hear when is warm. He told me than if i don't change every thing chain will broke and engine goes to trash -10K bill. Is this strokes on your car was whit bad theet?
Yes probably i'm gonna change the mechanic. If this chain not strechet better to leave or change it?

 

I suspected 😃call me 0895483336

 

@Drive-Maniac , good work! I have M272 with very similar issue (DTC 1208 only and nothing else). After dealers and indies visits, monitoring live data, I came to the conclusion it must be cam adjuster plate failure (worn area around the pin open and close). The parts aren’t too expensive (less than $500 for both adjuster, tensioner and pulse wheel), but the labor could be twice as much.