julioquispe

Greetings,


I am the owner of MBR Automotive in Utah. I often works on Mercedes and Foreign cars. My brother recently purchased a second hand 2013 ML350 and it developed a noise from the front of the car shortly after. The noise can be described as a Kocking/Chattering/Clanking/Rattling/Pounding type of noise.

Upon inspection, I had a strong feeling this was chain/tensioner related so scheduled him a visit at Benz since it's under warranty.

Techs at Benz described this as being a normal sound due to the DFI system. I refused to believe this from my experience with Mercedes.

I found the following information in both Mitchell and Xentry System. Hope this helps someone!

Topic number LI05.10-P-056435 (TSB)
Version 1
Design group 05.10 Camshaft drive
Date 07-16-2013
Validity Engine 276, engine 278, engine 157


Cause: Secondary timing chains might produce a rattling sound during engine start up until the engine oil pressure builds up. Once there is sufficient oil pressure created in secondary chain tensioners, they provide operating tensions to timing chains and the rattling stops. No consequential damage is to be expected.


Remedy: Install non-return valves (check valves) and replace left and right secondary chain tensioners as required. Install check valves by inserting them into the tensioner oil supply opening in the left and the right cylinder head. Correctly installed check valves and optimized secondary chain tensioners will minimize oil drainage from tensioners.


Order chain tensioners and check valves directly from parts with part numbers listed. Refer to the applicable engine number to install correct version of the secondary chain tensioner.

Note: Verify correct number or a sub through EPC as the secondary chain tensioners might be updated and part numbers could change.

Install check valves based on information provided in this document and measurements of the oil supply opening diameter in cylinder heads. Refer to the attachments for instructions on how to measure the oil supply opening and how to install check valves.

Note: Check valve installation special tool W276 589 00 33 00

Thimee

Can't speak for the V6 motor, but I had those check valves installed in my V8 (ML550) when it was still new, and it's been perfect ever since.

There is quite a long thread on the subject in the forum history, I suggest searching - it has all sorts of interesting details, including some videos of engines making the noises that are fixed by that TSB.

pcsgrp

My wife's e350 had that issue and it was the tensioners. Dealer gave me same run around that it was the injectors etc. I took video each time she started the car and after about 15 times, with the normal DFI noise, the rocks in a can noise popped up. When I took it to them to listen, they said it was the chain tensioner. Not having any similar issues with my 2014 ML350 so I guess it must have been a parts issue that they resolved

s400e

Hi
Xentry = rattling noise after engine start
for A276 820 03 000 15XX
?
is it the same solution that described for UP TO A276 8xx 03 001280?

Thanks

pcsgrp

I had the same problem on my E350 and I kept getting jerked around by MB. Finally after taking a video and they agreed to change timing chain tensioner. Be careful because about 15k miles later, the car developed major oil leaks around the tensioner covers and that was s costly fix. I don't know why it occiured, perhaps they didn't torque things correctly but it happened. After it was fixed, I have not had any issue

s400e

i read that on m276 engine; to change just the check valve.

juanmor40

Take a look at your engine serial number, and read the attached document. If you do not have your engine serial handy, you can get it from the VIN using https://www.lastvin.com/

s400e

Many Thanks
the engine number
276 820 30 001577
in the document= engine up to 001281

juanmor40

Definitely check valves . However, be careful the presence of noise (in particular if it has been there for a while) may have already cause some wear on the camshaft adjuster which will also create some additional noise (and I think misfires as well).

If you have a good mechanic, he can check for adjusters "clicking already" while installing the check valves.

juanmor40

Definitely check valves . However, be careful the presence of noise (in particular if it has been there for a while) may have already cause some wear on the camshaft adjuster which will also create some additional noise (and I think misfires as well).

If you have a good mechanic, he can check for adjusters "clicking already" while installing the check valves. For illustration purposes ONLY, a MB specialist will use appropriate tools and process for exact timing positioning