neomaxmaya

Hi,
I'm recently hearing a new knocking noise from my engine. Maybe I'm mistaken but would like to hear your thoughts.

The video is taken at normal temperature +80 Celsius. M156 on 2010 CLS63 AMG.


Thanks

vvrjrlaw

I don't hear a knock although the audio is not "memories" quality. I hear possible valve tap or injector noise (letting you know they are working) the engine appears to be smooth and the washing machine sound of all the pulleys and belts don't seem excessive. Perhaps you could describe. Understand that when someone in the auto industry says "knock" you're talking about bearing knock, wristpin knock and the like none of which can be heard from your audio.

neomaxmaya

Thanks for your reply.
I'm not that expert on what noise called what. but you can hear "the sound" at second 24 of the clip. its coming from the left side of the engine.
I scanned the car and no code at all.
Maybe I'm being **** about it and it's a normal engine noise.

vvrjrlaw

I've listened to the audio several times after you so graciously directed me to the 24 second portion of the audio. Even listened for a few seconds before and a few seconds after. It may be sound quality but I do not hear anything out of the ordinary. Under the circumstances all you can do is use your ears to see if it changes and be observant to any irregularities in the engine or its performance. Good Luck.

sircl55amg

it looks like valve tapetes .. common problem on that plaform...

https://mbworld.org/forums/w211-amg/...-included.html

neomaxmaya

Thanks for the reply. I have scheduled the car for a checkup in 2 days.
Will update you once figured out. I hope it's nothing though!


Neo

adl320

I wouldn't say you are paranoid. I test drove a 2008 CLS 63 with 64K miles today and heard the EXACT same noise. From the left side of engine if facing the car. Sounds like some kind of valve train noise. I get the "sewing machine" sound. Normal, but the tapping sound is what I heard too. I own a C55 with the M113 engine and mine makes that noise when cold but I don't hear it when warm. Perhaps this is normal? Any M156 experts here?

I really want to pull the trigger on this CLS But I think I'M overly paranoid of the head bolt issue. For reference, this car appears to be well cared for - I have all records from 20k to 60k, all done at their local Dealer. Would love to know what your mechanic tells you about the noise. I definitely hear it.


Aaron

brando111

PARANOID......
With some of the repair bills I've seen, I dont think you can worry enough.
I once had an estimate that had 5 digits, not including the decibal points.
That being said, I still drive it like it was meant to be driven

neomaxmaya

Well, the dealership said "the engin noise is within normal operation sound" and if I insist to open the engin and inspect, it would be on my own cost (rather than on warranty). So I lat it go for a while. However, I noticed that the tapping noise disappears when the engine is filled with oil as sometimes it gets low oil level where I hear the noise louder.
With further online research, it appears that the oil lifter sometimes doesn't pick up enough oil and causes such noise.

adl320

OP, have you noticed if your tapped noise has stayed the same or gotten worse? I DID pull the trigger on an 07 CLS63 and mine is generally very quiet in operation. I have twice though noticed similar tappet noise as you on cold starts but never when warm. The times I noticed it (I listen on nearly every cold start), it would go away in a few minutes.

This week, I noticed it was a bit more pronounced. I also noticed that it was a cooler morning than usual and the oil temp was a cool 36C. Again, it went away within minutes of driving off. I checked my oil and I was about 1qt low so topped off this morning. It seemed that for me, with low temps and lower than normal oil level, I was hearing the tapping. Never once warm. The engine is very quiet and silky smooth then.

I've posted a video of what it sounded like when the car was started cold with oil temp at 36C. I'll be keeping an eye on this to see if the oil top off solved my occasional cold start tapping like you. Just to note.