I'm going to drop this in here since it seems like a high traffic forum with a lot of knowledge.

I need to replace the right (US passenger) intake cam sprocket on my 2015 C400. It's an M276.8 DELA30 engine.

I'm really hoping I can get away with the somewhat cheaty way of replacing it without disassembling the top cam/valve cover. I ordered a kit from China (where they repair a lot of Benz's) that has a cam lock tool that takes the place of the timing chain tensioner and locks both sprockets against each other so you can stop the rotating assembly (well the cam at least) from moving while changing the sprocket out.

All that being said, I've reviewed many of the WIS pdfs here on the forums and I'm still a little unsure of the timing setup. Do I need the right intake cam sensor lobe to be halfway in the hole of the cam sensor before removing the sprocket? Is there a corresponding orientation of the crankshaft?

Also what's the easiest way to move the rotating assembly to achieve proper alignment with the intercooler still in place?

Thanks for any and all advice.

 

There are no two ways to reach the main balancer to rotate your crankshaft clockwise.

You're working on what is referred to as Bank1 Intake. Usually it is the Bank2 Intake that fails first.

Don't forget to replace limp TIMING CHAIN TENSIONER. Double-check the back side is smooth for a leak free mating.
Sand it smooth as needed!!


> Smart way!
The sprocket holder tool is the great way not to deal with needless long-way: valve cover RTV seal, fuel rails, injectors extraction, coils/boots, HPFP...


> Your job time...
You can make it easier to rotate crank by removing old sparkplugs if nearly due...
Use that opportunity for cylinders inspection + new plugs + boots.


> Factory T marks...
There are distinct sets of marks aligning the engine timing at 40° or 53° before No1-TDC:
-1- The reluctor marks through CPS holes
-2- The Phasers sprocket marks through timing cover


> Your own marks...
In addition to using factory marks, a nice fool proof way is to use a paint marker to mark the chain yourself on both In./Ex. sprocket.
Then transfer mark to your new In. sprocket as a quick double-check.


Last step to timing job is always to rotate crank 2 full turns to ensure valve clearance and all marks do line up.


> CPS/Reluctor faults ...
The camshaft reluctors are lightly pressed on and can move out of position given phasers ratling was ignored long enough. That causes a timing code.


> Unnecessary failure...
The phaser rattling is caused by low engine oil pressure stressing a single lock pin unable to stop camshaft from rotating.

Low oil pressure has many origins:

• Annual oil change schedule...
• Engine ECO Sart-Stop...
• Oil pump solenoid below 3500 Rpm...
• Euro 0w40 quickly becoming 5w30...

Where you can decide on 5kMi service interval with a better oil than basic stock.

 

Thanks for the reply!

A couple of quick notes and clarifications.

When you said "There are no two ways to reach the main balancer to rotate your crankshaft clockwise." did you mean that moving the intercooler out of the way is kind of inevitable?

like, "there's only one way"

Yes, fresh Mercedes tensioner is ready to go in, I'll make sure to double check flatness and smoothness. Thankfully I don't have any timing codes, and I avoided driving the car at all as soon as the startup rattle was detected.

I've had the oil pump solenoid unplugged for about a year, and always use high quality oil and filters, what's interesting is that this engine is quite low milage for it's age, averaging only 7000 miles a year, and my wife's car (another C400) has double the miles and not a hint of start up rattle.

 

yes remove intercooler.

What's wearing your VVT phasers are lock/unlock cycle count.
City vs Hwy Rpm have very different oil pressure profile... more pressure, less locking!

 

OK, just a couple of more questions, please bear with me I want to make sure I get this correct the first try.

I should lock the cam gears in place when:

A) the crank pully is on the 40* mark for TDC

*AND*
the bank 1 cam phaser sprocket marks are *upward* away from the crank shaft (visible after removing the cam sprocket cover)

*and* at this time the cam tone wheels should be centered in the CSP sensor holes

Also it looks like the crank pulley bolt is 27mm is that the "usual" size for the M276.8?

Normal running crankshaft rotation is clockwise, yes?

 

I imagine the 30 or so passes down the quarter mile drag strip weren't the kindest on the timing assembly either. My wife plays no such shenanigans.

 

Well you've got the idea about using timing marks but you'll benefit using the WIS procedure for exact details...

-- The sprockets marks point down towards the center, not upwards.

-- The reluctor wheels do not share TDC position with sprocket marks (40° vs. 53°)

meaning all 4x sprockets & reluctors are not all aligned at once but individually: either all sprockets or all reluctors.


>SIMPLIFICATION...
You don't have to deal with reluctors to time the new sprocket position.

 

thank you for the insight.

I think the thing I'm worried about the most is valvetrain spring tension causing the intake cam to rotate and making retiming more difficult.

This is the WIS pdf I've been referencing. Is there a better one?

https://mbworld.org/forums/attachmen...246d1561478209

 

you're right on that one... or droping the chain to skip over.

Thats why specific crankshaft position is used where cams are relaxed from tension.

Only thing that can help is double check marks afterwards and rotate 2x full turns CW or more manually to endure valve clearance ...

 

yes, I'm just trying to make sure I put the entire assembly in the position that relaxes tension as much as possible

did you look at the pdf I linked? it shows cam sprocket positioning with marks away from the crankshaft when using the 40 TDC marking, but I know that @S-Prihadi has found some "discrepancies" in the WIS documentation specifically regarding the M276.8 timing marks regarding the hpfp lobes.

I'm looking for real world experience with the cam sprocket marks (whether toward the crankshaft or away) for the "most relaxed" valvetrain/chain position.

Many thanks!

 

Now I understand your confusion about marks up/down.
Did you notice you're not referencing the right WIS procedure for Phaser replacement ?

 

I have never removed my VVT-sprocket yet, so I can't hel you much.
The :discrepancies" in the WIS documentation specifically regarding the M276.8 timing marks regarding the hpfp lobes.
Its only due to the 4 fuel lobes camshaft 3.0 turbo uses, vs 3 fuel lobes camshaft 3.5NA WIS uses for hpfp removal/install , the rest of timing chain matters are the same.

I am not at home, so can't acess my PC for WIS.

There are great and PROPER video on how to replace the camshaft vvt-sprockets.

You wrote :
I'm really hoping I can get away with the somewhat cheaty way of replacing it without disassembling the top cam/valve cover. I ordered a kit from China (where they repair a lot of Benz's) that has a cam lock tool that takes the place of the timing chain tensioner and locks both sprockets against each other so you can stop the rotating assembly (well the cam at least) from moving while changing the sprocket out.

Do it properly, dont do the cheat you intended.
That tool is dangerous, read here my explanation : https://mbworld.org/forums/e-class-w...-m276-8-a.html
If you want to sell the car after the repair, do what cheat and quickie is up to you.
If you want to keep it long term like me... do a proper job.

 

Do you have a different WIS procedure link?

 

Have you seen this video ?

 

Thank you JC
@JCM_MB

TwoC400's : I do not have a copy of WIS procedure for "phaser replacement".

It may be faster for you to locate existing thread about this topic - Pls feel free to link it here again.

You're right about setting the engine crank timing properly to stop cam from rotating once you free the chain.


> Other things to note ...
-- DO NOT OVERAPPLY RTV sealant on timing cover else it creates a fragile lip of RTV on the inside than can go plug tiny oiling passages regardless of filter.

-- DO USE SAND-PAPER to remove magnesium oxide on the timing cover - It is responsible for the ALT OIL SWAMPING LEAK - Factory video is wrong.

 

Thanks JCM_MB!

I had seen that video a few years ago when i resealed my wife's cam timing covers, but I couldn't find it again for the life of me. I'll be adding that to my bookmarks!

 

You are right. I forgot to add the "change" to the sealant procedure.

Here is a video from 603 MTechAutowerks (I think they are making a killing fixing these engines).

 

This thread couldnt be more perfect timing.
I just ordered a bank 1 passenger side intake camshaft adjuster from FCP (Febi) because OEM ones are $1170ish for just one.
I think these are failing due to the HPFP putting more stain on that cam sprocket. That coupled with stage 2 tune and E85, may explain why mine needs done at 102k miles but my wifes M276 in her ML350 has 168k miles on original ones, even with "extended" 7k mi oil intervals. Ive always done 5k max on my oil changes, and yes i do have the pump unplugged.
I have a shadow code P001177 as well, but you have to do a full scan for it.

Edit: should this be moved into the W205 C43 section? or does the W212 get more eyes? I just happen to catch it doing a search for cam adjusters.

 

Also, I havnt seen anyone recommend to replace the oil bolt/valve. I assume its just a clean and reuse?

 

The combination you describe are interesting to try understand what top stressors increase lock-pin wear...


Driving style seems to be in it for something besides oil service, total mileage, oil choice,

I am not sure what part of HPFP system helps/hurts the Bk1 phaser.

• A lot of time Bk2 wears out first
• V8 use dual HPFP
• NA HPFP use 3x lobes cams
• Turbo HPFP's use 4x lobes cams

If you're going the long way to replace your Bk1 Intake Phaser passed 100kMi. then consider replacing your HPFP roller-follower and/or pump itself.

 

The roller replacement crossed my mind but I won't be back there because I got the timing lock kit. Plus I need to repair my passenger axel boot and do motor mount. Enough work for the car for now.

 

I would definitely replace the cam sprocket bolt while there. I'll be replacing the sprocket, tensioner, cam sprocket bolt, both CSP sensors, both VVT magnets as well as the pressure sensor on the intercooler.

 

This is why we need an M276 specific engine forum.

 

"The sprocket bolt" is called the "variable timing solenoid pressure valve".




or the "central valve" in the MB EPC.



If the engine has been through extended oil services and low quality oil, the valve may be sludged within so I very good clean up or replacement is recommended.

On the P001177, it can be:
0 - Check for oil in the solenoid actuator connector -> Action: new solenoid actuator, clean connector, and check at the other end of the harness -> ECU for oil migration
1 - The solenoid actuator. Action: swap the solenoid actuator with another one (neighbot camshaft one), and rescan. If the code moves -> NEW solenoid actuator
2 - It can be a dirty pressure control valve "bolt" -> Action: Clean/Replace.
3 - Actuator is no longer working as expected -> Action: NEW Actuator

Before replacing an actuator, I will always check that the tone wheels are centered in the camshaft sensor port holes when the engine is at timing at 40 deg. Just in case, though, I would have expected P0016/18 instead if the tone wheel slipped.

Also, from another forum member (in Germany), this store refurbishes the VVTs ( https://mehenker.com/en/)
My 2c.

 

I hear you... enough parts for this garage queen!

The lock-kit is the perfect way to go. There is zero stress passed through the skinny chains.