DeTh

Over the few years that I have owned my car (2013 E350 Mercedes), I've noticed that every now and then on starting the engine, I hear a loud clanking noise from the engine bay. Through my research, I've discovered the timing chain tensioners are a problem with this engine.
Reading the V3 of the TSB from LI05.10-P-056435, and my engine number being 276952 30 310339, the stated fix is to install check valves and chain tensioners. (Part numbers A 276 050 25 00, A 276 050 26 00 for tensioners, and A 278 050 40 00 for the check valves).

My question is, can I replace this myself?
What other information and tools do I need, and how difficult/expensive will it be?
If I don't fix the issue, what is the worst that can happen?
Has anyone done this themselves?

I attached the TSB for anyone interested

CaliBenzDriver

correct me... I think we have 2 kinds of startup rattles designed to call for attention:
- From the non-ratchet loose chains tensioners
- From the unlocked loose VVT gears

It may be that replacing both leaking timing chain tensioners and adding the missing check valves does not cure the startup rattle if the VVT pins are already wasted.

Regardless it's a great idea to prevent lack of lubrication at the engine rear (fuel pump, camshafts aluminum bearings).
When the timing chain tensioners leak internally, the available pressure at passenger side becomes dismal.

I am curious... does someone know how many VVT gear get wasted:
1x Passenger vs. Driver engine bank
2x Intakes
2x Exhaust
4x All $$$$

Not sure but I'm leaning towards "Passenger Intake VVT" only

The hardest part maybe rotating the crank one-way with a breaker bar to align camshaft timing marks.
😆

Chevota

Maybe this will help, it's a video of the procedure. I personally feel like he's cheating because the engine is out which makes it so easy, but of course better for us to see.

The VTT issue is more involved, but luckily for us there are lots of misc vids on doing stuff like that.

CaliBenzDriver

5NM torque on aluminum screws... what is MB trying to accomplish with these loose covers?

I can see there is not a lot of stress on these covers besides the VVT solenoid oil plungers.

Why not just use injected plastic covers like the intake plenum with snaps and use the fancy screws budget on dependable ratcheting tensioners??

BenzV12

If you have skills or happen to be Edward China why not ?
The worst thing could be a major engine failure which would be $$$$$ to fix .It doesn't sound as easy as replacing engine oil and engine filter