Hi have a question for some of the more technically advanced people on this forum and I hope I don't catch too much heat.

I recently performed the secondary timing chain tensioner replacement on both Bank 1 and 2 on my 2014 GL450 with 140,XXX miles. The job went very smoothly, I marked the chains and sprockets on both sides to be EXTRA sure that the chain hadn't moved while reapplying tension to the timing chains. Pins pulled, new tensioners installed, no movement at all on the timing chains. Reassembly went well (the drivers side is awful if you don't remove the oil filter housing) and everything gets put back together. No leaks, car fires right up, runs smoothly, drives great.

The next day my wife is driving the car and the CEL comes up. P0011(77) - position of the intake camshaft on Bank 1 deviates from the specified value.

Things I have checked so far.

• Timing looks ok
• Cleaned and swapped VVT solenoids from intake to exhaust - still have the code after erasing it
• Cleaned Cam shaft position sensors
• Verified that the reluctor ring is centered in the CSPS port

Is it possible that the reluctor ring moved on its own in the meantime? The car was running perfectly with 0 codes until after I performed this. I have been doing some reading and have come up empty handed apart from the possibility of having to replace the Bank 1 intake camshaft phaser which sounds terrible. If anyone has some pictures of what position the reluctor ring should be in the port hole of the CSPS I would really appreciate it. I doubt the phaser is going bad since everything was running perfectly before and at this point I have almost convinced myself that the reluctor ring has moved.

Can anyone provide some insight into WTF just happened. For some reason there is a good amount of reference on the M276, but nothing for the M278. I have referenced YouTube, forums, Superetka and Alldata and there is almost no info. I have the Foxwell NT710 to help pull data. For reference, Bank 1 intake cam position is showing at 42-43 degrees according to the scanner data

HELP! I can provide pics upon request and will upload some later this evening when I get home.

 

BUMP.

Any insight would be appreciated!

 

After doing some more diagnostics I am starting to conclude that the camshaft phaser has gone bad. Does anyone know if it's possible to replace the camshaft phaser itself without removing the valve cover and camshaft itself? I have seen a few different types of tools that allow for this but want to see if anyone has any experience trying this. I could make this into an evening project if I don't have to remove the entire valve cover, but if anyone has any additional info I would really appreciate it!

*I guess some people call it the camshaft adjustor*