Misdiagnosed balance shaft gear failure
I pulled the engine out and got the timing cover off only to find the balance shaft gear (all gears driven by the timing chain for that matter) were in excellent condition. There were no signs of wear at all, everything looked like new.
I've not been able to confirm timing chain stretch as the closest to a stretch test I can find is the valve opening relative to the crank angle. I tried to follow the data set out in WIS (no actual procedure provided, just data) but found that it wasn't making sense as the angles were so different that it would be completely impossible to the chain to stretch that far without breaking or causing the engine to not even run
I ended up checking the links around the cam gears and found minimal movement which would suggest the chain has not stretched.
There does appear to be some wear on the chain guides and I was wondering if anyone has had experience with the guides causing P0016/P0017 errors.
Could this also be a sensor issue? I also replaced the magnet on the exhaust cam so I wouldn't expect both P0016 and P0017 errors.
Any thoughts?
Last edited by Splint3048; Aug 12, 2017 at 11:54 PM.
I can't recall but does your P codes indicates right bank only?
The chain and gears look to be in excellent condition and when I pull the chain tight around the gear there is negligible free movement of the links around the chain. If the links were stretched the first and last links in contact with the gear would engage tightly and there would be some free movement of the other links in contact with the gear.
The markings on both the gears and the sensor disk line up as per the manual, meeting along the mating face of the head/cam cover and the other marks perpendicular to the mating face in the upward position with the crank at 40° ATDC.
I also checked the piston TDC using a dial indicator with respect the TDC on the harmonic balancer, all good.
Given that the base timing is all good, I have some suspicion that the tensioner may not be applying sufficient force to the chain guide allowing the gears to advance slightly due to valve spring forces. The doubt surrounding that theory is that there has at no point been any issues with chain slap.
I also suspect that there may be issues with the sensors. I could swap them around and see if the fault codes follow the sensors. Not sure about the cam adjusters either. The repair kit comes with a new tensioner and magnets, so there is a significant possibility that if I to put it back together all will be ok. If not I'll need to take it to someone with a start tester and look at the live data to try and see what's going on with it.
I've included a couple of images of the balance shaft gear so you can see the condition is clearly good.
As the front cover was off, I used a dial indicator on the piston crown to find exact TDC. I then bolted a piece of wire to the front of the block and bent it around to align with the o° on the harmonic balancer. I then rotated the crank to 40° ATDC and observed the correct alignment on the timing gears.
I then rotated the crank to 305° and noted misalignment of the inscription.
I rotated the crank until the inscriptions were centred through the sensor holes. At this position the crank was at 315°.
I then put a dial indicator on the number one intake valve (right bank) and rotated the crank until the valve opened exactly 2 mm. The pointer was in a region of the harmonic balancer which does not give an angle value. I rolled a steel rule around the circumfrence of the area and did a little maths to determine tthe crank position was at or near 56.5°. The specs indicate the crank should be at 38.2° which would indicate a stretched chain. I'm a little unclear regarding the value ...1.8°. Anyone able to clarify that? Obviously not closing as that is covered further down and cannot be the left bank as that is also covered (not shown), also not a tollerance as the figure of 28.8 is shown further down. Any suggestions?
Even though there is no obvious signs of chain stretch by trying to move the links while held tight over the cam gear, I'm satisfied that the chain is stretched and plan to replace it.
Trending Topics
The easiest way to check if there are any problems with the chain is to get a icarsoft MB2 and and watch the real time position of the cams as the engine is running.
You should find the intake cam positions being the same between left and right banks. Same goes for the exhaust readings, they will be identical to each other as well. The variance I've seen between intake cams is 0.5 - 1.0 degree maximum even as the engine is running.
Last edited by - Mover -; Aug 24, 2020 at 12:03 PM.
The Best of Mercedes & AMG
The easiest way to check if there are any problems with the chain is to get a icarsoft MB2 and and watch the real time position of the cams as the engine is running.
You should find the intake cam positions being the same between left and right banks. Same goes for the exhaust readings, they will be identical to each other as well. The variance I've seen between intake cams is 0.5 - 1.0 degree maximum even as the engine is running.
Good day!
I have recently got a w211 M272 - E350 and after oil change comes the dreaded P0016 / P0017. I have been following your thread as I too am certain that I don't have a balance shaft issue.
I checked the knock sensors - All good
Opened the manifold to check if any issues there - All good (Clean valves

Through the Carsoft MBII, found the values of the right bank to be stuck to 36.20 (Inlet) & 20.00 (exhaust) throughout, whereas the other bank was showing change in values.
Could this be the current to the right bank and sensors be the problem or would I have a stretched chain?
Out of curiosity, why would the right bank timing be stuck to one value (Retard position)
I would be grateful for your guidance as the car does have rough idling and heavy fuel consumption due to this. Any help here would be grateful!!
I've included a couple of images of the balance shaft gear so you can see the condition is clearly good.
As the front cover was off, I used a dial indicator on the piston crown to find exact TDC. I then bolted a piece of wire to the front of the block and bent it around to align with the o° on the harmonic balancer. I then rotated the crank to 40° ATDC and observed the correct alignment on the timing gears.
I then rotated the crank to 305° and noted misalignment of the inscription.
I rotated the crank until the inscriptions were centred through the sensor holes. At this position the crank was at 315°.
I then put a dial indicator on the number one intake valve (right bank) and rotated the crank until the valve opened exactly 2 mm. The pointer was in a region of the harmonic balancer which does not give an angle value. I rolled a steel rule around the circumfrence of the area and did a little maths to determine tthe crank position was at or near 56.5°. The specs indicate the crank should be at 38.2° which would indicate a stretched chain. I'm a little unclear regarding the value ...1.8°. Anyone able to clarify that? Obviously not closing as that is covered further down and cannot be the left bank as that is also covered (not shown), also not a tollerance as the figure of 28.8 is shown further down. Any suggestions?
Even though there is no obvious signs of chain stretch by trying to move the links while held tight over the cam gear, I'm satisfied that the chain is stretched and plan to replace it.
I have the same issue with p0016 I just ordered all the parts I need and was looking at your pics and the 2nd picture of the balance shaft has signs of wear on the plastic ring theres a channel worn into it and it’s not that way on my new parts I assume your issue is your balance shaft
I have recently got a w211 M272 - E350 and after oil change comes the dreaded P0016 / P0017. I have been following your thread as I too am certain that I don't have a balance shaft issue.
I checked the knock sensors - All good
Opened the manifold to check if any issues there - All good (Clean valves

Through the Carsoft MBII, found the values of the right bank to be stuck to 36.20 (Inlet) & 20.00 (exhaust) throughout, whereas the other bank was showing change in values.
Could this be the current to the right bank and sensors be the problem or would I have a stretched chain?
Out of curiosity, why would the right bank timing be stuck to one value (Retard position)
I would be grateful for your guidance as the car does have rough idling and heavy fuel consumption due to this. Any help here would be grateful!!
The far left cam needs be adjusted one tooth counterclockwise without removing timing chain you must remove valve cover to adjust though be sure to do research on removal as you need to pin the intake cam sprocket to make reinstalling exhaust camshaft easy
also I’d recommend right down any codes and erase them all to see what comes back as the new code may be your only current issue that needs attention the mb2 scanners work well then try swapping the 4 cam sensor to opposite banks ie swap side and check if any codes change positions ,if codes stays on the same bank then it’s mechanical not the sensor
The far left cam needs be adjusted one tooth counterclockwise without removing timing chain you must remove valve cover to adjust though be sure to do research on removal as you need to pin the intake cam sprocket to make reinstalling exhaust camshaft easy
also I’d recommend right down any codes and erase them all to see what comes back as the new code may be your only current issue that needs attention the mb2 scanners work well then try swapping the 4 cam sensor to opposite banks ie swap side and check if any codes change positions ,if codes stays on the same bank then it’s mechanical not the sensor
my camshaft that has the chain on it on the left of side when looking at the front of the car ie intake cam is only retarded one tooth but if you try and slip the timing chain a tooth you will now be advanced by a tooth on outer gear which has marking dots which will still give a code. Do not adjust timing chain cam if retarded one tooth moving the chain move two teeth on outer wheel
And if your retarded one tooth on intake cam side ie inner cam then adjust exhaust cam one tooth ie outter camshaft
counterclockwise that will get ride of p0017
just make sure all timing marks line up properly before removing cam and also camshaft is in a unloaded position do not turn engine with camshaft out or valve cover off they should all be torqued before turning
been driving this way since I bought the car 123,000 now at 134,000 still going strong
also had a fueling issue seems to have been either purge valve was blocked just blew air threw the line or was fuel pump relay for $18 from mb
Kunalrm has similar issue to mine, but luckily after replaced magnet, sensor and wiring on exhaust, P0017 is gone leaving only P0016. Interestingly, intake side is where seal/sign is dead center.
Curious in Kyle issues and solutions: after observing cam in real time, where Exhausts on both side doing its jobs well, Intake on bank 2 could be as much as 36.8 degree as well, only Intake on bank 1 fluctuates well at idle and under load too. But then, at some point (after pulling off gas pedal), it will return to idle position of 36 degree and then stuck (open/close) there?
My conclusion: the adjuster plate near its dowel pin has worn that prevent the pin from open/close as needed. Plan to replace intake adjuster (part 2720505347) along with possibly its valve and timing tensioner if needed. Any thought, feedback, comment?
One thing I am pretty sure: DTC 1208 doesn’t have to be balance shaft, some MB documents even stated that it doesn’t apply to W204. And especially when there are no other symptoms. In my case, simply one adjuster among 4 on both sides was failing. That’s all.







