lifters replaced but still hear tapping
 

Factory warranty was coming to an end and Ive been hearing a slight tapping sound for the past month from both heads towards the front (closest to the radiator). Noise was only present when the engine was at normal operating temp and didnt increase with rmp. Only 26xxx miles on my 2014 which seemed like low mileage for worn lifters. Nevertheless, dealer verifed the "noise" and replaced all 32 lifters. Got the car back today and the same noise is still there but Im only hearing it from the passenger side head and not the driver side. So Im not sure if the lfiters were the problem

In the video you can hear the specific noise Im reffering to right at the 10 second mark and last until 15 seconds when I move the phone. Any ideas what this clack clack clacking is?

work order
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Sounds like the camshaft adjuster pin slapping back and forth. I have the same sound on my ML and gave up trying to fix it.

Just enjoy the car. They all make noise. You’ll drive yourself crazy if you try to eliminate every little sound. ¯\_(ツ)_/¯

Gave up because you replaced the part once and the noise came back? Or just decided to stop chasing the noise?

I certainly enjoy the car to fullest but not knowing if certain noises are causing internal damage or could eventually lead to a failing part is enough to get it looked out.

Keep an eye out for a new thread labeled "whats the whinning noise" lol

Run a thicker oil

this noise only happens when the oil is above 220. Doesnt happen cold. Switching to a 5w40 from the 0w40 Im using now wouldnt provide any additional beneift at operating temp correct? Just at startup

However, I was planning on switching to Liqui Moly 5w40 next change anyway

Correct, as the hot viscosity is the same in both oils.

Is the 0w40 Mobil 1? Try Motul 8100 5W40 or as you mentions liquid moly. Toss some Ceratec in there too. The hot car tapping has gone away for some (including me and I read it here) by changing from Mobil 1. Should it matter as the weights are the same? No. Did it get it rid of the tapping? Yes.

The dealer replaced the intake adjusters under warranty and the noise continues, so I had to live with it. Seen many M156s suffer from this noise.
Regarding the thicker oil, I ran LiquiMoly 10w-60 in the summer as it gets more than 50c, and noticed a quieter engine. However, I saw a note for the M156 (In Mercedes Bevo), restricting any weight other than 0w-40 and 5w-40, so I am back with Mercedes genuine oil 5w-40.
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I wished they made a 5w45 8100 oil it would be a perfect oil for our picky top ends

It’d be perfect if you determine the health of your engine by how it sounds, and not by what it actually requires to work from an engineering perspective.

you kill me....

....but I do agree about the enjoy the car part of it. Our engines make ALL KINDS OF ****ED UP noises most of the time..2° change in temp, new noise...storm front moving in, new noise.... humidity changes, same noise different pitch......They are not LS engines(not knocking LS), they are over engineered precision machines that are very sensitive to a plethora of minute variations in a multitude of scenarios.... If you hear DAMAGE occurring then by all means check it out, but if its just an "odd" noise I say ride out

Having read the posts here two things occur to me.
Why at 48000 km (30000 mi) am I not hearing anything? Have to listen closer when I get home from the frozen east!
Second, if you are planning to keep the car for some time maybe consider an after market warranty at least on the drive train. If nothing it will give you peace of mind and if you buy one that is transferrable then you can negotiate that with a buyer.

Exhaust leak?

Had this on my c43

Yes mobile 1 0w40. Next oil change Ill make the swap

Its hard to hear the specific noise Im referring to in the video but its definitely not the lifters. It only happens when the oil is hot. 225+. Tech told me the oil thins out when it reaches that temp and is likely the cam adjuster. He verified the noise.

I have the fidelity platinum coverage and this will be my first claim.

That’s a fantastic policy. They’ve covered over $20k repairs on my old M5. Recently covered the clutch/flywheel too.

Let us know how they respond to your first claim.

So I had both cam adjusters replaced on the the right side. Tech told me that the noise got worse when he put the new adjusters in so he replaced them again. I dont even know how thats possible unless maybe he didnt lock the adjuster correctly. But he put 2 more adjusters in the next day and he claimed the noise went away. I pick up the car and its still there. Hmmmmm....so obviously it wasnt the adjusters.

Yea, there probably isnt any damage occuring and these motors make noise....I get it.

However, Im thinking it may be a faulty chain tightener/tensioner. Since this noise only happens when the oil reaches 225ish +, the oil is thinning out and maybe not giving enough pressure to push the tensioner piston into the chain guide causing the chain to slap on the guide or maybe not properly mesh with the idler gear? Thats why the noise isnt a constant clack clack clack clack clack. Its more like clack clack pause clack pause clack clack

Trying to think of other options. Thoughts?

Mine makes some noise as well. sounds like a hydro lifter or some hydro lifters dont like cold start. funny sound only at the right bank. when the engine is warm or hot there is still a slight tappering noise between 1400 and 1600 rpm. I tried all possible addatives and it gets better....for a week.. when the car stay for about 4 to 7 days at home all the noise is coming back. a top mercedes mechanic told me that is normal. the sound frustrate me.
I have read so many threads about this problem in forums arround the world it seems to be normal.
In 3 months I will run on the german highway and hopefully after 8 hours driving the hydraulic lifter will be cleaned out and back in live.

many years ago I had an bmw e39 540i manual transmission. the car had the same noise from hydro lifters and some guys had a engine damage. so some day I decide to solve this problem. many weeks later I found the source. The spring in the oil pump of the pressure valve wearned out....funny the oil pressure was still o.k. when I compare the lenght of the old and new spring there was 1 inch diffrence. after installing rhe new spring everything was fine.

That's not a tensioner noise imo. I have replaced them several times on m3's and when they fail to hold oil pressure the noise is much more pronounced. You can easily hear the chain slapping/grinding the guides and it doesn't have a rythmic cadence like that...much more chaotic...if that makes sense. I'd also expect to hear a pronounced rattle on startup if it was tensioners.

I'm thinking that if it is the tensioner, the tensioner hasn't completely failed yet but perhaps the seal around the piston is starting to fail. My noise only happens at idle when oil pressure is at the lowest and when the oil is hot and thin. When rpms increase the noise goes away

have same problem, did you found what is it?

in most cases its the cam adjusters and NOT the lifters.

if you meant that problem with rattling on start, there is no rattling, only that clack clack clack on 80-100 degreese hot engine

oil brands and weights can play a huge factor in noise as well. if you're using mobil 1 try another oil. many here use other oils than mobil 1 with great things to say.

also, best you upload a video for us ... that is the only way we could give any solid advise.

sound same as on video from topic author, it's absolute clone, I have that problem right after lifters replacement, I tried several oils and nothing helped or related to sound at all, so problem seems somewhere else, it's sounds not like something is wrong at all like lifters problem. Anyway thanks for trying to help.
I tried motul 5w-40 with ceratec, mercedes original and mobil.