I think 2014 USA CLS also has the updated chain but not the return valves. Am unsure about the tensioners.

the tensioner, correct, but also check valves for the cylinder head so that the oil cannot flow back or away from the tensioner.

Antimatter Hi, busy like always but all is well thanks for asking.

I checked mine I defiantly have the unrevised first version chain in my engine, very disappointed, now I just checked Mercedes part catalog and guess what, since two weeks ago they revised that already revised tensioner in your hand ( part# 4700) you been comparing it to the first version that’s causes all these cold start noises that people hate with part# 0064, now like you always say, Go figure.

@@SlickJeff2020 Benz has a kit with 3 check-valves but based on what Tasos is showing, the oil is really leaking directly from the poor tensioner (steel piston sliding in an aluminium bore: genius!)

so to fix cold start (low/delayed oil pressure) timing tensioner rattle... dont bother with check valves BUT CHANGE TENSIONERS for the latest UPDATED VERSION. The original version was made to leak [big aluminum bore and a small piston to guarantee oil leak] The newer version limit oil leak without adding any seals by having a closer tensioner piston to bore adjustment. Question: why do they purposely make everything borderline junk??😂

@@glasser2819 is the oil leak a serious issue? It would be a shame if you have new chain and tensioner but get oil leak and have to replace tensioner.

I don't think you need to remove the engine for a timing chain. Note-- haven't done it yet, and I guess it depends on the car, but have worked on other timing gear (5.0L Jaguar SC).

Yes

i can confirm this for a 2012 m278 at an official Mercedes service shop in Germany. Old Chain checked ok, new tensioners and check valves. Timing diagnosis using Xentry proved totally fine and not close to any limits from the degrees at the cam adjusters. 68' km on the clock.

But why? Labour is same so isn't it better to just get new chain whilst there?

@@ruhelamin1952 Actually, swapping the tensioners does require less work and effort. Here is a link to the MB procedure: kzfaq.info/get/bejne/n5mBqMlpytTMg58.html Plus, if the old chain is okay, why change something that is working as it should. Generally, as an owner, i feel that taking care of the issue is good but depends on how you use the engine. I cannot clearly say what makes the difference, but most cars with m278 that are simply driven will show a worn timing chain between 150 and 230 thousand kilometers. I have seen plenty of videos from people owning a m278 car and that do have the rattle on startup but do not even say something about it. Like, "it has always sounded that way" so why complain. If i wasn't informed about what to look for when buying a m278 car i wouldn't have noticed either. So, long story short, and as Mercedes state it in their documents for the procedure, most likely you will be fine (for a normal lifespan up to 200.000km i assume). Of course, as an enthusiast, i wanted to have everything done so that now with 72.000km on the clock i can be sure that the engine will stay in top shape for years to come.

CarGuy TV hi, at least they find the problem and they fix it but with the m156 they didn't do nothing with the camshafts issue. Thanks

Tasos Moschatos i thought when you repleace camshaft to the new one it will silve the problem . I thought m156 original camshaft was just made from wrong material or something . But yeah how sad

CarGuy TV The M156 production lasted 9 years. It doesn't matter if the car is a 2006 MY or 2015 C63 507 (the final M156 engine) camshaft and tappets issues are still occuring. Heck, I've seen valves hitting the pistons more so on later M156 engines, due to damaged tappets.

Hello. I also noticed my car does this. when I start it cold and drive off I just press easily on the accelerator and it goes away. Its not too bad for me now

lucky you it will be cheap, here: oily crankcase breather causes dirty throttle body to mess up the idle position. The Fix: - clean throttle bore and flap - service crankcase breather Furthermore: all the oil that got sucked in created "carbon" deposits on intake valves... So concider removing your intake plenum and cleaning valves when doing an early spark plugs change. I wonder if master Tasos approves my diagnosis/repair assessment..? 👍🏻

I also have that "problem" it only happens when the engine is cold. No need to worry, when it gets warm it drives smoothly. My car is stock btw.

Bayhas Kana yes this is for the timing chain tensioner to keep some oil pressure inside when you turn off the engine

Tasos Moschatos from that video, it sounds like these one way valves can help both new and old style tensioners if the 157 is making rattle noise at cold start, is that correct ?

Bayhas Kana the M157/M278 engines from 2015 and up they already have this valves, the engines with the old timing chain doesn't have these valves unfortunately.

Tasos Moschatos great to know! Sounds like I need to take my upper cover off and see what version tensioners I have exactly, it’s a US 2014 GL63, I can see I have newer chain through oil filler, and EPC is saying I have newer tensioners... yet I get the 5sec rattle at cold start, will see

@@bayhaskana7439 so what did you find? What's making the rattle