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2012 E63 with the older timing chain. I’ve had long cranking/starting with CEL corresponding to P001785 (cylinder bank 1 exhaust cam out of sync with the crank) and noticed on Xentry that the exhaust camshaft position on the right cylinder bank was out of range.
Proceeded to change that adjuster magnet, cleared the codes and first start was fine. Subsequently the car once again took longer to start and threw the CEL. Got back into Xentry and am seeing this:
As per the test procedure in Xentry, voltage to both intake cam sensors is ok, which points to faulty sensors. But what are the odds that suddenly BOTH sensors are bad, especially since they were both within range before I changed the right exhaust cam adjuster magnet? Further diagnosis on Xentry also shows this:
My right exhaust camshaft is still out of range, after the adjuster magnet was changed. Would the reading of -25.00 degrees of my right exhaust camshaft automatically be wrong given I don’t meet the test prerequisites due to my intake cam sensors? Or more critically, does this indicate that my timing is slightly off?
I’ve read the threads from amgboy916 below, but don’t want to jump to any conclusions: https://mbworld.org/forums/w212-amg/733002-m157-timing-chain-stretched.html
https://mbworld.org/forums/w212-amg/736454-m157-owners-beware.html
What would you suggest as my next step here? I don’t want to replace the intake cam sensors and not resolve the issue, again since the odds of both intake sensors all of a sudden being bad are slim. Thanks everyone.
Swapped the camshaft sensors and got the exact same results on Xentry. So according to Tasos, my timing's off and either the chain has stretched/jumped, or potentially one or more bad pulse wheels/adjusters.
Swapped the camshaft sensors and got the exact same results on Xentry. So according to Tasos, my timing's off and either the chain has stretched/jumped, or potentially one or more bad pulse wheels/adjusters.
Car is still opened up as I can only work on it a little bit at a time. I’m at the point where the timing cover is going back on and then reinstalling everything in front that had to come off to do the work.
Guess I’ll never know exactly whether it was either a timing chain or cam adjuster (or potentially both) since everything is being changed at the same time.
Weird that non of the M157 gurus here chimed in! Best of luck to you, how many miles did your engine have when this happened?
Thanks. Symptoms started somewhere around 90k: longer to crank intermittently, then every time. During this period I was doing the usual…swapping cam sensors and changing out the adjuster magnets. Neither changed the output on the Xentry tests.
If you're getting consistent implausible errors. Then my hunch is that there's something mechanically wrong and not a sensor.
Usually when a sensor goes bad, the implausible is truly implausible. For example one of my suspension sensors every once in awhile throws and implausible reading, when it's supposed to be arrange of -0.5 to -1.5, it'll show like positive +6 for a few minutes and then go back within range
I wonder how many degrees each tooth would make the cam off by? I bet you it's probably when in range of a tooth or two.
Well, in the end it doesn’t matter whether it’s cam adjusters or timing chains because either way you’re going into the timing case - would be foolish imo to replace the timing chains and not the adjusters and vice versa. For the amount of time and effort to get in there you take care of all of it.
Of course, taking care of the cam adjusters without doing the chains is fine so long as you have the updated chains. I had the old chains.
And as far as changing the timing chains as per WIS and simply feeding the new chain while attached to the old one, I wouldn’t advise doing it that way. Although this method allows you to leave the timing cover in place, it doesn’t allow you to replace all the plastic guides and rails around the chains - and mine were in BAD shape at 90+k miles. You should also be replacing the smaller chain that goes between the intermediate gear and the crankshaft while you’re in there.
Last edited by amgggg...; May 29, 2023 at 06:23 PM.
Car is still opened up as I can only work on it a little bit at a time. I’m at the point where the timing cover is going back on and then reinstalling everything in front that had to come off to do the work.
Guess I’ll never know exactly whether it was either a timing chain or cam adjuster (or potentially both) since everything is being changed at the same time.
Im going thru the same thing with my 2012 e63 m157.. been sitting at the shop for months.. timing chain issue Any update on yours
No updates yet, my pace of work has slowed to a crawl lately… but I will update when it’s back together, regardless of success or failure.
I was at the point of reinstalling the timing cover but after double checking my work I realized one of the chains wasn’t properly lined up - disaster averted. So I had to disassemble and reassemble again.
What’s also complicating this a little bit for me is that I made the decision to do the chains and adjusters without removing the valve/cam covers.
I just started tearing into this. Got to the point of removing my valve cover, which I will do tomorrow. I spun the engine over and didn’t notice and clicking or slipping on the camshaft adjusters, but once I get the valve cover off I’ll check before ordering anything.
Like you I am getting the P001785 but also the P00185. My Bank 1 exhaust is showing a value of -25 degrees.
This is on my 2012 ML63 but it has the updated timing chain.
Yeah once you get it done the key thing according to Tasos Moschatos (YT M157/722.9 guru) is to change oil every 5k miles/8k km. He estimates the chains can easily go 180-200k miles with more frequent oil changes. If changing oil only at 10k miles or more, he says it’s possible to have issues as low as 100-120k miles. I have no reason to doubt this and figure it’s especially important if your car has the non updated chains like mine did.
The other IMPORTANT thing is to never let your engine run low on oil i.e. CHECK the dipstick rather than waiting for the message to come on the dash display. He discusses this here:
Can’t really post the WIS since there are many, many sub procedures to follow in terms of removing everything that needs to be removed, tech info for double checking timing (you can go to Tasos on YT for this too just search “M157 timing”), torque values, etc etc
In other words, you should already be equipped with this info before diving into the job. This is not where you want to be simply winging it. I did hours and hours of research online - even having WIS - before I dug into it.
Well opened up the valve cover tonight, and I think my camshafts are done. I am not a engine internals expert by any means, but any input by the guys looking at this thread?
Hi!
My Metris is showing the same code. Did you find a solution? This code is driving me crazy.
The timing is perfect, new sensors (camshaft, crankshaft, magnetic VVT solenoids .....) , new chain, clean oil, new camshafts adjuster valves, chain, ......everything is square.
Now, I was wondering if maybe the problem is just the ECU, and I should take it to mercedes to reset or update it.
Thank you!
Hi!
My Metris is showing the same code. Did you find a solution? This code is driving me crazy.
The timing is perfect, new sensors (camshaft, crankshaft, magnetic VVT solenoids .....) , new chain, clean oil, new camshafts adjuster valves, chain, ......everything is square.
Now, I was wondering if maybe the problem is just the ECU, and I should take it to mercedes to reset or update it.
Thank you!
You don't need to guess, simply look at live data.
Specifically the correction factor to your camshaft position.
Don't mess with ECU updates. Deal with the issue itself.
Hi!
My Metris is showing the same code. Did you find a solution? This code is driving me crazy.
The timing is perfect, new sensors (camshaft, crankshaft, magnetic VVT solenoids .....) , new chain, clean oil, new camshafts adjuster valves, chain, ......everything is square.
Now, I was wondering if maybe the problem is just the ECU, and I should take it to mercedes to reset or update it.
Thank you!
You dont mention camshaft adjusters? Could also be a reluctor wheel on the camshaft. Have you looked through the cam sensor ports to verify timing as well?
Perfect timing (I did it with the camshaft positioning tool and after finishing the job carrying a visual check through the camshaft positioning sensors window and positioning tool), new VVT valves (Camshaft Adjuster Oil Control Valve) and new camshaft adjusters, new sensors. Today a double check the basic timing procedure and the timing is perfect. I exchange the sensors (intake and exhaust), check the voltage, exchange the camshaft magnetic solenoides, installed a new crankshaft sensor. Everything related to timing is square, but I still get this P001785 code. perfect timing, perfect voltage, new sensors......etc.
At this point, I am just suspicious about the camshaft exhaust control valve, that it is not doing the job because it may not get enough oil pressure to do its job or about the ECU........
Any advises?
My next step is taking it to Mercedes. I did my very best ......
Perfect timing (I did it with the camshaft positioning tool and after finishing the job
carrying a visual check through the camshaft positioning sensors window and positioning tool),
new VVT valves
Camshaft Adjuster Oil Control Valve
and new camshaft adjusters,
new sensors.
Today a double check the basic timing procedure and the timing is perfect.
I exchange the sensors (intake and exhaust), check the voltage, exchange the camshaft magnetic solenoides, installed a new crankshaft sensor. Everything related to timing is square, but I still get this P001785 code. perfect timing, perfect voltage, new sensors......etc.
At this point, I am just suspicious about the camshaft exhaust control valve, that it is not doing the job because it may not get enough oil pressure to do its job or about the ECU........
Any advises?
My next step is taking it to Mercedes. I did my very best ......
Thank you
I re-read your long list of maintenance parts. Good job to ensure engine keeps running
-- Can you see the positioining difference your ECU is flagging?
-- One thing... did you clean the mesh-filter on the oil-valve core at center of VVT ??
-- Whats the mileage on your chain-tensioner ??
-- Some ppl have replaced chain + sprockets for excessive play. Don't guess, test!
Last edited by CaliBenzDriver; Jul 2, 2025 at 05:58 PM.
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Any update on yours
