Hey guys,

My M156 is in a W211 but I figured the W204 forums get more action so I'd post it here. Anyway, I think I may have the dreaded tappet tick issue that has turned up on a lot of these engines. I believe its only on the right cylinder bank. Here's the link to the youtube video if you wouldn't mind listening to it and letting me know your opinion:


Let me know how bad you think it is and how urgently I need to replace the tappets and cam. I really don't want it to bust a whole in the tappet and ruin this engine...its spectacular!

Anybody get MBUSA to cover the work??

Does it go away once warmed up, and what oil are you using?

I took that video with it at operating temp, 81 degrees C.
I've always used Mobil 1 0w-40. Thats the right stuff? I know Merc says to now use a 5w-40 but that only changes the winter viscosity...

Mine has done that once. And I took it for a drive and it went away and has never come back. Is yours now constant? If so, take it in asap.

If not, at a minimum, I'd bring it to the dealer and complain about it so that you have it on record. Not sure where you are but in CA, if a defect manifests itself during the warranty period, the warranty does not expire until the defect is fixed. That language is on the reverse side of every repair invoice the dealer gives you.

Edit: You are on LI (I'm a Smithtown native!) and NY likely has the same basic warranty law.

If it's constant for extended time period I'm going with cam adjusters. What year is your car? Google cam adjusters there are a couple videos but sound always comes from the drivers side for some reason. Do you have a rattle sound from that area on startup?

If it's just during warmup I wouldn't be too worried about it as it's just not fully lubricated yet...if it's constant or does it when warm I'd get the cams and valve buckets checked

Nice! I'm in Dix Hills.

I'm out of warranty at this point (probably a mistake) but I called MBUSA earlier today so at least its documented. Apparently they haven't settled the lawsuit over the issue (?) If its settled, at least I'm documented and could have something re-reimbursed.

The sound is constant even after warm up. Whats the story with the cam adjusters? It is only on the drivers side. Are they defective and often need replacing? or are they just typically noisy and theres nothing to worry about?

I work at a dealer and we had an E63 come in with a very similar noise. There is a bulletin out that calls for replacement of camshafts and tappets. $6,000+ in parts alone. After this was done the noise was gone. If it was my car I would do lifters alone. I'm assuming they want the cams and tappets to wear to each other, but at that cost I would take my chances.

There was no noticeable wear on the cams or tappets. The test to see if they need to be replaced is to push on the lifter and see if they feel "soft". In my opinion it was not the best wording. Using a brass punch and arm pressure you could feel some of the tappets give under pressure.

Is try new cam adjusters first

Yeah I guess I'll pull the valve covers off and try this test, I'm not sure exactly what "soft" means but maybe I'll notice it on only certain tappets. I just hope to god the cams are fine!

This really blows my mind that Mercedes isn't fixing this. Its a pretty incredibly devastating issue for the engine considering it only has 58K on it!! @layzie12G Did that owner of the E63 you worked on get his cams and tappets replaced at cost? or did Mercedes pick up some of the costs?

Actually Benz did pick up all of the cost. I guess the car has had various engine issues since it was new. That is the only reason. If you car has been healthy up until now, I would assume your on your own.

Jeeze, well that sucks. I think it'll make more sense for me to just trade this thing in...

The lawsuit you are referring to was dismissed, no settlement, I cannot remember the details.

My car also has the ticking, and a slight high pitched rattling has developed which is a little worrying, but I am at 110k miles and almost a year out of warranty. Not sure what I am going to do.

Yeah I'm getting out of this thing. Its a shame, such an incredible engine. It just doesn't make much sense to spend $6k on a car thats worth $28k, I'll just trade it in at $23k and consider myself lucky!

Mine started tapping today, but I haven't driven or started it for almost two weeks.

This happened when it was sitting for nearly two months last year when I traveled a lot.

I think that's a different issue. Apparently when they sit for awhile they just need oil to circulate, apparently the engine has drainage issues or something. My problem is persistent whether it sits for awhile or not

My 2011 had the nasty ticking. It was under warranty as a CPO. The dealer tried twice with the lifters, cam shaft etc, no luck still ticked. I ended up with a new M156 freshly shipped from Afalterbach.

If it has been sitting, does it and then goes away after warming up I would not worry, but if it is a regular and persistent problem then would suggest having it diagnosed and repaired. Need good techs to do this.

Yeah I'm just dumping the car. I have no interest in spending $6k for new tappets and cams...too bad though, absolutely loved this car!

Shop around. Labor time is only 6 hours to do the job. I would just replace the lifters if it was me.

mine makes an intermittent tamping... it's totally random. dealer checked it, said it was fine.

do you have the SB for this?

I do not.

i'll keep an eye on the car... it's already logged into the system about the ticking. so i guess if the engine blows, they'll just have to get me another one.