m276 Valve Cover Removal
 

I need to remove the right (Passenger) valve cover on my 2014 M350 M276 engine. My latest road block is getting the components off the rear of the cover.
There is a bracket there that has 1 screw easily accessed.
Is there a "how to" or step by step description available for this?
Can I remove the valve cover without disassembling the rear?


Alex

M276
 

Here's a picture of the bracket that I need to remove. This picture is from an eBay auction. My engine is still in the car.
3 mounting screws are out (1 on left side, 2 on back).
The unit wobbles as if it was held in by a plastic clip somewhere. Most likely towards the bottom?
Is there another mounting screw somewhere? Does the bracket pull out?

Thanks for any help,

Alex

There is 4 bolts holding it , in your first picture its below the left arrow, 2 in the back and the one you can see, get yourself a mirror on a stick so you can see,there should be a wire bundle clipped into that big bracket , use a forked panel popper tool to pry it off the bracket,your going to have to remove the rear exhaust shield on the right side, then after all that' take off the breather at the back of the head

Another clip?
 

nulu,
Thanks for the info... it took all day but I got the valve cover off.
I don't see any markings on the camshafts. I borrowed a friend's cam alignment tools and it seemed like the intake was off by 2 teeth. The exh cam guide fit but the intake didn't … it was very close.
Very possible considering the ugly noises I heard while attempting to install the new tensioner the first time.

I removed the tensioner and played gently with the crank loosing the chain and was able to get the cams where they should be... I think.

Both alignment guides fit on the cams. I don't see any laser lines, hash marks, scratches or anything... but now the alignment guides fit.

Looking at the pictures, does this make sense?

I sure do appreciate you sharing your time and obvious knowledge.

BTW I believe that I have the crank set to TDC. Both cams have lobes pointing NOT at the #1 cyl valves valves and the crank markings are pointing up. It's kinda fuzzy and worn but it looks like TDC.
'
Are these cams set right?

Alex

Marks
 

Well now that the sun has died down a bit (doing this job in my driveway), I am seeing some marks.
Do these marks indicate the exhaust cam is off? With the crank set at TDC #1 I believe.

Alex

It looks like this chain comes pre marked to assist install and only the 2nd pic has the marks lined up. This would only assist in initial assembly because the chain isn't going to land in the same place after a revolution.

If the cam tools are being properly used, that is what you need to go by. Also, be sure that TDC is actually where the crank should be when using the cam tools. In order to prevent valves hitting pistons, some engines are timed XX degrees off TDC . Some engines also have a way to index the crank with a pin / bolt.

If you haven't loosened the cam / crank sprockets, the cam tools should slide on but again, this does nothing to confirm crank position is correct.

Please expand on " ugly noises I heard while attempting to install the new tensioner the first time. " were you cranking the engine with the starter / by hand or was something else going on?

The marks for cam position are on the camshaft back side, not looking from the front looking at the rear on the camshaft plate with the cutouts , and the cam timing gets set at 40 degrees , note the hash marks are hard to see, but when crank is correctly set , those cam hash marks are level with the surface of the head, those other marks at front are for a new chain installed with copper links to line up to, ie a copper link lines up on crank and the copper links line up with adjuster marks, such as a new chain installed.

The noises I heard when moving the crank by hand, I believe, was the chain jumping a sprocket. I will check with my buddy that lent me the tool to ensure proper piston position... TDC or 40 ATC.

re marks: So the crank is set to the 40 mark and then the cams are aligned using the hash marks? The marks are not the ones in reply #5, the marks are on "the adjuster."

I'll set the crank at the 40 degree setting and look for hashes.

re the chain copper marks: understood.

Get'n close
Thanks
Alex

Hi Nulu,

Are these the marks for setting the cam timing?

Alex

absolutely not, those are for when a new chain is installed on an engine undergoing assembly those dark marks are for lining up a new chain , which you would set a copper link to the mark, then a copper link with the intake adjuster and one copper link with the exhaust adjuster ,you would only see the mark on the crank with front cover removed , timing is verified with the marks at camshaft plate , or by removing cam sensors and verify a certain position of camshaft plate viewed thru timing sensor holes.

OK Back to looking for the for the marks.

I appreciate your time and patience. I do not want to attempt to start this engine (or even begin reassembly) before I am dead certain I have the cams timed and aligned correctly.

Alex

Interesting MB put marks on for initial assembly but did nothing to make it easier to set without the tool going forward. Oh well.

I can't offer up anything to help the thread but may possible be here one day I'm following it to learn. Whenever I've done timing belts/chains I've always spun em a bunch to verify no interference before buttoning it up and trying with the starter.

I verified 100% mark at back side of camshaft (just behind adjuster) , a flat lazer marking should be level with the flat surface of the head, you can barely see the mark,hash mark

Cam mark
 

Hash mark within circle, exhaust cam

Cam mark
 

Should look like this at 53 degrees disregard 40 degrees

Cam Marks
 

WOW absolutely great shots! Unfortunately I just cannot find marks like those anywhere on my cam plates.

I have these two "Tools" and neither one helps locate any marks like the ones you pictured. I am currently attempting to determine whether I have a M276.8 or M276.9 Engine. I believe it is a .9 but the service rep from MB should be calling me back with the specific number. Once I know which tool to use, I'll attempt to align the cams with it.

I searched with both tools on both backing plates on the cams and cannot see any marks like the ones you show. I sure wish they were visible.

I will check again after the sun goes down a bit to eliminate some glare.

I understand that WIS AR05.20-P-6010GQ shows positioning of cams at 53 degree timing mark, with the valve cover mounted. I am going to try that.

Alex

you can zero in on correct marks by comparing left side if left side wasn't disturbed,by looking at 53 degree line up of cam sensors, a light shining on the mark from an angle helps

OK I found the exh mark (just like your picture!) after removing the cam.
There is only 1 mark on the intake…/ could this be it?

Alex

yes, can you take another pic further back, I want to see the cut outs

Int Marks
 

Whatcha think?

By the way, Thanks.

Alex

put that intake cam in the head clean and lube set the lazer mark level with the head at 40 degrees, put the two holdown tabs on the cam, then the exhaust then the tensioner, do not rotate with the valve cover off, if you want to check you can install most of the vc bolts and test by rotating 360 twice and pulling valve cover and checking that your marks lazer marks are level with the head,or make new paint marks at the adjuster to front of the engine but I would use the laser marks, remember don't confuse 53 degree check that's only used to check adjusters thru the cam sensors holes in the valve cover , you add17mm to 40 degree mark , because some motors don not have a 53 mark, they stop at 40, so you add a strip of tape 17mm to the 40 that's your 53 mark, at the 53 degree mark timing is checked thru cam sensor holes

Cam mark
 

Info

When all 4 cams windows are visible at 53 degree mark thru the sensor holes your done

Amazing.

Thanks for the help. I certainly would not have gotten this far W/O ya.

I'll post progress.

And now...

Alex

Cam mark
 

Cam timing

Looking at picture in no.18 ,it does look like a picture I found in wis, of lazer mark at intake

Cam mark
 

Picture of intake

Update:
Cams are lubed, installed, aligned.( a little tricky)
Tensioner installed.
Valve cover cleaned, sealed, installed. Screws torqued to spec plus mode 2 (90 turn)
Front cover cleaned, installed, torqued.
New plugs in, new plug wires, all torqued and installed.
Breather inspected, cleaned, installed.
High pressure fuel pump inspected, installed. Fuel plumbing installed.
ECU installed. connected.
Now working on brackets, cables, hoses, and what the %^&* is that's.
Tomorrow expecting delivery of 6 lower intake manifold gaskets... last parts needed (I hope).
I'll post when it starts.

Thanks NULU for the critical info.

Alex

Halexb - did you remove the center firewall insulation to remove the upper intake manifold? If not, how did you access the two bolts at the rear of the manifold? I ran into this issue earlier this year when I replaced the spark plugs. The WIS calls for removing the upper manifold but I could not remove the wiring harness from that center section of the insulation. With that insulation in place I gave up trying to access the bolts and did the job with the manifold in place. No fun - the driver's side was a bear. Any advice would be appreciated.

Hey Vince,
No, I chickened out of that. The two screws at the back are brutal but there are some good things about them.
The screws are set through rubber collars and won't fall out when they are unscrewed from the engine. Once they are loose stop turning them.
They are the same as the front two screws so the same socket will work.
The area of the manifold the screws pass thru in the back is different than the front. The front is a well type of configuration and the back is not. see pictures.
The upside down picture shows the "removed" screws retained in the manifold.
I used a long Torx socket, and an extension to get them started. Once they began to turn I switched extensions and finally unscrewed them by hand.
It's tight back there. And it's far away from the front of the car.
I used a blanket to cover the engine, a short step ladder to boost me off the ground, and layed out over the engine to get closer to the task at hand.
I dropped a few sockets and extensions and finally removed all the underside pans.... and found an oil leak... but that's for another day.
Very cramped quarters indeed.

Alex

Thanks Alex. Considering your experience I feel it is probably preferable to just wrestle through the plug change with the upper manifold in place. The driver's side is really tough; the passenger side is fairly easy.

Why did you have to take valve cover off?

Do y'all think the reason MB sets up timing marks as something other than TDC is because at the setting they have it everything is as "relaxed" as engine can get? No pressure from valve train trying to move cams in other words?

To use the cam locking tools he has.

The primary reason is to have all of the pistons slightly down in their bores. This prevents bending of the valves if a piston is fully up and cam is turned.

This step of having pistons down in their bores is also very important when installing heads / cams on most any other engine even if it is times at TDC.

Thanks for explanation.

Hey all, I am late to this party but am about to try this exact repair on my '13 E350. I had a failed tensioner on the passenger side bank, went through all the steps to replace the tensioner at 40d but still have codes being thrown so I am certain I jumped time a tooth or two.

My big unknown is once I reset the engine to 40d and verify the driver's side is in time, is it just removing the camshafts on the passenger side, set them back in the correct time, make sure everything is aligned?

If it's just the intake camshaft out of time can I just rotate that one?

Thanks in advance.