M271 engine Questions on camshafts sprockets alignement
Thread Starter
Newbie
Joined: Oct 2020
Posts: 4
Likes: 2
C180 CGI 2011
M271 engine Questions on camshafts sprockets alignement
Hello all,
Long story short, on my 140000km 2011 1.8 turbo C 180 I had an engine light that would disappear then come back and a fault code pointing at the intake camshaft sensor which I changed but no improvement. Tthen I heard a short diesel sound for one second every now and then and starting would take a couple of seconds more than it should.
I decided to open up and fit a new chain and tensionner.
I’m almost done but there is one thing annoying me which i’d Like to double check with expert advice please:
I attach pictures of my camshafts markings before and after, I am happy with the all the markings bar one, the one on the outboard of the intake camshaft sprocket is not aligned with the one on the inboard ( camshaft side) of the same sprokef assembly , is it normal or an issue?
The Mercedes documents to check alignment says :
The camshaft adjusters (3) require no particular adjustment, as they automatically take on a basic position to the camshafts when engine is vertical
Can I crimp my chain and fit my tensionner or do I need to fit a new intake sprocket assembly? ( they seem pricey)
Before new chain intake side:
Exhaust side before:
Exhaust side after:
And the one that annoys me, intake side after, you can see the markings on each side of the chain is not fully aligned.
Cheers guys,
Olivier
Long story short, on my 140000km 2011 1.8 turbo C 180 I had an engine light that would disappear then come back and a fault code pointing at the intake camshaft sensor which I changed but no improvement. Tthen I heard a short diesel sound for one second every now and then and starting would take a couple of seconds more than it should.
I decided to open up and fit a new chain and tensionner.
I’m almost done but there is one thing annoying me which i’d Like to double check with expert advice please:
I attach pictures of my camshafts markings before and after, I am happy with the all the markings bar one, the one on the outboard of the intake camshaft sprocket is not aligned with the one on the inboard ( camshaft side) of the same sprokef assembly , is it normal or an issue?
The Mercedes documents to check alignment says :
The camshaft adjusters (3) require no particular adjustment, as they automatically take on a basic position to the camshafts when engine is vertical
Can I crimp my chain and fit my tensionner or do I need to fit a new intake sprocket assembly? ( they seem pricey)
Before new chain intake side:
Exhaust side before:
Exhaust side after:
And the one that annoys me, intake side after, you can see the markings on each side of the chain is not fully aligned.
Cheers guys,
Olivier
Thread Starter
Newbie
Joined: Oct 2020
Posts: 4
Likes: 2
C180 CGI 2011
Hello
I will answer my own question and maybe it will be useful for someone else later:
I decided to reopen the chain ( I had not crimped it yet on purpose) and test the adjusters for free play, the exhaust side is nice an tight, the intake (i.e. the one with the annoying alignement) can rotate a few degrees. Ref the video I made:
I have opened it, not much to see, the inside looks very much like the one in this video which had the same symptoms than mine if you watch the previous video on this guy’s channel. Clearly the pin and spring do not do their job anymore which explains the transitory rattle noise when the oil pressure is low during start and the camshaft sensor code.
Conclusion I have ordered a new intake adjuster and the bolt ( which includes the valve system) that I damaged when I removed it. And that hopefully will allow me to put everything back in order!
I will answer my own question and maybe it will be useful for someone else later:
I decided to reopen the chain ( I had not crimped it yet on purpose) and test the adjusters for free play, the exhaust side is nice an tight, the intake (i.e. the one with the annoying alignement) can rotate a few degrees. Ref the video I made:
I have opened it, not much to see, the inside looks very much like the one in this video which had the same symptoms than mine if you watch the previous video on this guy’s channel. Clearly the pin and spring do not do their job anymore which explains the transitory rattle noise when the oil pressure is low during start and the camshaft sensor code.
Conclusion I have ordered a new intake adjuster and the bolt ( which includes the valve system) that I damaged when I removed it. And that hopefully will allow me to put everything back in order!
Super Member
Joined: Feb 2007
Posts: 601
Likes: 285
From: Republic of Texas
W203 W212 W211 R53MCS
Intake camshaft adjuster is one of the most common failures on these engines. I highly recommend, since you are already there to do the exhaust side adjuster too. I have done many of these repairs at my shop. If you you inspect the intake adjuster you can see how the spring is actually digging into the metal where it rests....... If you inspect the exhaust adjuster you can see how it is also starting to do dig in.
