vincheung

What brand and grade of oil are you currently using? If it's quieting down when things get to operating temp I would lean towards oil related.

Tylek Douglas

mobile1. 0 w40 full synthetic not quiet but not as loud

jcat

that's the right oil, I wouldn't expect the ceratec to magically fix this issue but might help some.

Tylek Douglas

I removed the Vbelt and yes the sound is still there .

Tylek Douglas

I put the two cans in and went on a road trip just got back home almost 600 miles later it’s still there. Smh I don’t even know what to do at this point.

VII

With what you've described I would lean towards a bad lifter but would scope the bores to make sure there is no premature wear.
Too bad there are no cam covers anymore as a simple next move would been to remove and inspect.

Tylek Douglas

Thanks for your help. I’ll try a shop and have them to scope it to see what shows. If anything I’ll report back when I get an answer for anybody in the future. I’ve found nothing online about this issue.

cfmistry

Unfortunately that does not sound good.. I also believe it to be interference from the cams. I have heard about this issue on other M278s but it is very rare. Please let us know what you find!

Tylek Douglas

Thanks I definitely will.

Tylek Douglas

Is there a way to check the valves with just taking the valve covers off ? I’m leaning towards a valve issue

VII

IIRC the 278 does not have a valve cover, at least not a traditional you can just take off and put back on.

Edit: Yes with the integrated cam journals the "cover" is more comprehensive and will require the removal of the front cover and ancillaries at the rear on top of the DFI injectors, so a couple of hours extra per side.

VII

You can get a preliminary view of the valvetrain from just the cover but to be able to really check things you'll need to remove the cams.

DaveW68

That noise "could be" the hydraulic chain tensioners. This is a known issue with the 2014's. It is rectified by adding a check valve to the tensioners. MB TSB #LI05.10-P-056435. You should have your local dealer or MB mechanic diagnose it to see if this could potentially be the problem.

Tylek Douglas

Had these checked today. They are fine. Indy said he’s almost 100 percent sure it’s a hydraulic lifter. Any suggestions on the job?

As you all can see
I already started tearing it apart.

Tylek Douglas

Do you know where I can get the instructions on removal ?

Tylek Douglas

Thoughts ?