Hi all, I have the popular rattling/knocking sound for the first 5 seconds and then dissapears on my m278. The sound is coming from the left side so I decided to open it up. I found that the chain tensioner on that side is bad and I will have to replace it however I noticed that I don't have check valves installed so I have to ask the dealer if I have to install them. Not totaly sure if my sound is coming from the bad chain tensioner or from a bad camshaft adjuster. Some people have a faulty camshaft adjuster that was causing their noise and after replacing it resolved the issue. I'm not sure if I will replace the adjusters because I'm not sure if they're bad and those are a little challening for me because you have to take the whole top off and injectors etc. and make sure I don't mess-up the timing. Does anyone here know how to check the camshaft adjusters to see if they're bad without taking them out and also if anyone can provide a workshop manual on how to replace the adjusters and tensioners?

Notice there's no check valve installed.


Thank you all.

 

I had the adjusters replaced on my 2012 with 100k miles. they are not cheap but i was able to source them oem and cheaper than my dealer. my indy mechanic did labor for one bank for around 1800 including a new tensioner. i did check valves plus tensioners myself and the noise continued. i believe you might be able to use xentry to see if the adjusters are faulty. when i had the timing cover off like your photo, i spun the engine by hand and oil would squirt out of the bad adjuster i had, i would try to spin it with the chain tensioner in place. good luck