Does anyone know where I can find this? I tried ebay with no luck, and the online websites that do carry them want 160+. Just trying to find an alternative. What did you guys use to install your check valves?
Part Number:



This is what the tool looks like...

w276589003300

you can easily fab one at your local Home Depot

What was the problem? Tell us more about what you were doing.

when the engine was first introduced, there was a (non-critical) flaw regarding engine start up sounds. Adding that check valve as well as replacing the chain tensioners was a remedy.

The notorious cold start rattle, so I ended up swapping out the chain tensioner for the new part number that was recommended in the TSB for the m276. My engine number fell under the numbers affected. I also add in check in valves into the head, behind the chain tensioner is a hole. I pushed it in by hand till I couldnt anymore, then used an old chain tensioner housing with a flat metal bracket behind it to push the check valve in. Its in, almost exactly flush...a little part sticks out and I didn't want to push it and risk stripping the bolts or damaging the head.

Appreciate your sharing this post. It really helps when there's no resources regarding this 276 engine issue.

can you please share the part number of the tensioner and check valve? where do you buy it? how many of them needed?

Plus, how did you manage to press it in?

thanks again.

how did you remove the check valve?
Half of mine got stuck in there

You can buy it on Amazon.

Ouch!
These valves are mostly made to go in but not out. MB used two designs:
1- The one with threads behind shoulder flange is good to gently pull

2- The valve with deep shoulder and outer threads: don't mess with it! It's guaranteed to split up nightmare.


Now you are left drilling and cleaning shavings... a road less traveled. Take all the time you need to clean up mint like new.

While at it, polish the tensioner mating surface smooth to hold oil pressure well. This will give you a well timed engine without any camshaft jerkings.

I have two spare perfectly new check valves with no use. I was stopped by the factory parts not being the cooperative type.


thread near shoulder are removable

In 2013 the factory installed the "Do not disturb" check-valves parts... so I chickened out with no valve replacement.

No problem there! The issues are with the limp tensioner shaft seal and the engine oil pump low output control.


polished aluminum tensioner surface

My new in a box MERCEDES BENZ tensioner parts came from factory with a lip defect on the mating surface - I had to polish one smooth so both tensioners got sanded smooth. Note: for some reason, there is no sealant used to install tensioner.
Surfaces better be nice and true.


air bleed vent hole

Air present inside the tensioner can acts as an air cushion - We don't want that to keep chain tight!!
A tiny hole is provided to help flush air out at the expense of a minor internal leak.

I'm trying to figure out how screwed I am. This little plastic end piece for the tensioner fell off and went down into the engine. I saw it and tried to grab it with some tweezers, but it fell down beside the chain.

... I see! You know dont kill yourself over it, this has happened before -


Your choices may be...:
- A - spend some time fishing or vacuuming it out...
or
- B - go ahead and replace a known engine killer seal on the TIMING COVER on the way change all 3 TENSIONERS. (first timers: 5 to 10 Hrs - Equipped PRO:90mn)

May the force be with you on fixing this . Through in a Serpentine kit , water pump, thermostat... sparkplugs/boots/(coils)... and still be doing a lot of good for your car.

Thanks Cali, moral support is important at times like this

Being a child of the 80s, I always hear the A-Team theme when I am able to pull something like this off. Although McGyver may be more appropriate.





With that crisis averted back to the main job. I assumed I needed the new tensioners because I was getting a rattle on cold start. However, the new model tensioners and check valves were already in place.

I would assume that the chance of the check valves failing is relatively low so I should leave them in. However, I do have some 5mm screws and could rig up a puller to take them out.

Has anyone seen the check valves fail?

Based on other posts on the forum, it seems like my best bet may be to replace the tensioners, switch to 10W40 and home for no rattles.

I got the GLK with around 60k miles and now it has 116k miles. The tensioners must have been replaced by the previous owner.

Thanks

Congrats... McGiver really flipped that challenge around in a victory


These type of factory check valves are best left alone as they have the shoulder flange away from the threaded outer section....
you pull,
they split up,
you're screwed!


Besides nothing wrong with factory valves so long they were not left out at production time.

No question: these engines can rattle with or without valves installed!


> 100k start-up RATTLE ...:
The worned intake Bank1 HPFP needle roller require increased forces that stress the semi-empty VVT gear and tensioners.
Remedies are new parts and lubricants with improved viscosity in the upper W40 range.
Old tensioners develop internal leaks
Old VVT Gear chew up steel lock pin
Rattle produced by either lock pin and/or limp tensioner.

There is no way to cancel that issue without swaying from factory standards. Engine lubrication requires more frequent 5kMi oil change with stable viscosity in the upper W40 range.

Rattle is the audio reminder that your camshaft timings are loose all over the place. This directly de-tunes engine performance while pressure does not matched with stiff HPFP.

Reduced oil pressure under 3500Rpm help produce this rattle while giving us an easy way to prevent it.

So, the new tensioners are in with the existing check valves. The old tensioners were within 1mm in length of the new ones extended. The old tensioners when fully retracted will no longer extend, is that an indication that they have failed?

Other than that, I have spun the engine by hand with marks on the can sprockets and things seem to be staying in line (I saw a video where this was the test for the VVT gear). There is a pronounced click every now and then but the marks stay aligned on the cams.


I can't really take on opening up the valve cover right now. Is there anything else I can do, other that button things up and hope for the best?

Thanks for all the help.

yeah valve cover is a whole different ballgame with high pressure rail.

You can inspect Cam Position Sensors for traces of oil leak as well as VVT 4x Solenoids for oil leak through...

The old tensioners that get hanged inside match what the new ones that can do that as well.
I think the big deal is the rubber bearing of tensioner shaft gets cooked soft and leaks to allows travel instead of reliably holding tight.

As far as VVT clicking loose, sounds like a failed unit... likely the passenger side intake Bank1, right?

Even if the lock has failed you can help counter that with better oiling conditions away from MB "MOD-0" standards.

Extended rattling may cause camshaft reluctor sensor wheel to shift after some time when neglected under limited oiling conditions.


Having a well timed camshafts without looseness is going to let your ECU learn more responsive timings.
🤞

Actually the clicking is the new driver's side tensioner moving in and out. At times it is 100% compressed and then will suddenly extend maybe 30% out as the chain tension lessens.

I took it out and checked to make sure it would actually extend 100% and it does. I guess it would have more force when it is pressurized with oil.

Not seeing this behavior with the passenger side tensioner though.

Oil pressure is what keeps the tensioner ram from going backwards. Without oil, only a weak spring is
We've seen the oil pressure is insignificant for tensioners efforts exerted on the chain guide.
we could use any liquid at 5Psi and nearly get the same results as oil at 50Psi holding chain slack.

I got everything back together and the rattle has reduced, but now I get a P0021 camshaft position, intake/left bank 2 - timing over advance. I don't think I could have jumped a tooth on the timing belt, but I guess that it possible. I replaced the solenoid on that cam today, no change.

Would I get this code with the VVT failure?

It happens... sometimes the timing belt goes bad ... lol

In reality we're running CHAINS that are quite long lived.

Your cam code may be STORED or caused by one of VVT vs. Tensioner vs. reluctor wheel .

Yes, a high quality German chain not a belt like a Caravan. I acquired a copy of WIS and will find the procedure to check the timing that was used in this video:
I didn't have a check engine light before I did the tensioners. So, I must have somehow slipped the chain by a tooth. However, based on your posts and other research on the forums I suspect a VVT is in the future for this car.

... did you happen to disconnect all that with batteries still connected ??
then ECU registered an issue with position sensors.


> ANASTASIA CONDITION :
Try to DISCONNECT BATT'S before disconnecting parts of your choice else ECU or SAM will register bad input and switch over to default values.
​​​​​​​
Fix:
Reset faults > Reboot chassis > Rescan.