Iqless

After having the car sitting for a few hours or when first cranking in the morning the engine gives a knocking sound, almost sounding like drums, and it disappears after a couple seconds.

I currently have 5-30 synthetic oil in it, tomorrow putting 0W-40 with a Mann OEM filter. Will that solve my issue?

Should I be concerned about this or should I take in to a dealer? I hate to take it to the dealer since I barely trust any of them, and they usually always fix one thing and brake another...

I heard this on several M272 engines, then again, some don't do it. So I am wondering if the oil should take care of it.

Thanks,

Plutoe

Knocks, as you describe are very difficult to translate into words and create a post about a drum like sounding knock----many folks will have a predetermined cause----that does not offer any help!

I doubt that an oil change would solve the problem, unless you are about five quarts low.

The best I can offer is lift the hood have your girlfriend start the car while you try and determine the location and duration of the drum sounding knock and report back!!

baggee

Knocking sound that you hear comes from timing chain.Chain is loosen or tensioner is bad.In each case you must replace both items...

Iqless

Timing chain loose? What about after those 3 seconds? It tightens itself? It's a knock that appears to go away as soon as the oil pressure gets up.
Well I will just leave it like this, as some say its normal and some don't. I don't want the dealer to come up with decisions to take engine apart, as I know they only want to take advantage of warranty and just replace something to make money.

06E5004ME

Loose timing chain or tensioner will sound more like a chainsaw and will be constant. As far as I know, timing chains/tensioners have not been problematic on the Mercedes engines.

Iqless

What do you think about this noise? Listen carefully from 40-55 seconds. It comes, and goes away. It is very obvious, of course with the radio off.

When sitting in the back seat I kind of feel the vibration.

What could this be?

baggee

Yes,it is sound from chain area.Go to the dealer or some other workshop for diagnose and my teory will be confirmed.It is not normal sound and with time it will be louder and it will last longer...

Iqless

Knock at engine start after sitting overnight has been identified: Main bearings, too much clearance... Need to replace them under warranty.

I wonder what else may pop up in the life of the vehicle, right now just 42k miles on the clock..

06E5004ME

I can't hear anything out of the ordinary in the clip you posted. Can you hear it outside? It's hard to hear anything from the inside due to the plethora of sound insulation. With 42k miles on the car, I highly doubt that it's timing chain or tensioners. That problem is more common at 100k-150k miles.

This is what a loose chain/tensioner sounds like:

06E5004ME

Could you be a bit more specific? Which bearings? I'd like to know just so I can keep an eye out.

Iqless

I will post more detailed info when I get the car back with the input from the dealership.

But here is a video from youtube with the same engine noise at start up that I have:

baggee

How did they come to conclusion that bearings are bad? Did they dismantled the engine? Did they at least take off oil pan? There is no other way to diagnose bearings without one of actions what i mentioned.Sound from bad main bearings will go louder when engine reaches operating temperature and it is noticed any time you hit throtlle,it can't be heard only on engine startup.In yours case there is some other things hangin around,not just main bearings...

Iqless

I have no clue man it's with them they should know what to do and they also should let me know all the details once it's ready for pick up.

WHTEVO

Main bearings will not knock and go away. Rod bearings will knock. Either way, it's under warranty so no worries.

Iqless

Thanks man, but do you think the car is gonna last after that engine rebuild, as some say it will have problems down the road since engine has been taken out and worked on?

WHTEVO

/\ It should be like new if they do it right.

Iqless

Just a call from MB dealer, knocking is normal and won't affect performance or longevity of the engine. The ticking that I showed in one of my videos is coming from a purge valve, they will replace it under warranty.

The knock will be documented as "normal" for future protection when I'm out of warranty.

Anyways, I have to trust them and I will live with it.

No faulty bearings whatsoever.

Thanks

swisal

Had a similar problem on my C63. The dealer did the following and its fixed. Replace intake and Exhaust CAM Adjusters. Under warranty, otherwise cost $ 3 grand. Kept the car fora week.
dearer did a great job.

Titus

There is an open campaign to replace the boot on the adjusters. Warranty should replace the bad adjuster.

The Thomas J

Sounds like piston slap to me. Used to get a similar noise on one of my N* motors. From what I understand piston slap develops when there is too much carbon in the engine. The solution is to do a WOT as often as possible.

eboueiri

I also own a 2004 C230K. I used 0W-40 and Mann filter. When it gets cold outside and the car sits for a while, I get a rough engine noise and very weird and loud but quick rattle in about 2 sec after start. I did a lot of research. read many threads. took the car to many places including the dealer. No one can legitimately or accurately diagnose this issue. My latest finding is that it is oil related but more so the 0W-40 oil. While it is a great oil, it is too thin for this engine. Most if not all the oil settles at the bottom of the pan and especially when its cold outside. 0W-40 is designed so that it is thin when cold and thick when it warms up. so the colder it is the more likely you will hear the noise versus hot days or warm engines/Oil.

That being said, I have yet to find a better oil or an additive for this engine [M271] that is Mercedes approved and fixes this issues without causing other problems. in my opinion, a thicker oil or an additive or even an external oil pump along with the engine oil pump that can start prior to starting the engine could be a good fix especially if implemented before any wear has taken place.

No healthy engine should sound like this.

Sleeper Benz

I like that solution

3164MALIK

Friends,
I just joined and need help. Could anyone diagnose and help with the above noise. The video above !
I have a 2009 E230 and makes exactly the same noise as in the video.
Sincerely,
​​​​​​​3164MALIK​​​​​​​

Samsd

I’ve just bought My car from a private seller and it is having exactly same noise and it happens even when car isn’t start., if I just press start button once quickly abs have ignition on, the noise will come after few minutes for few seconds abs go away and will come back after 10 mins or so and keep doing it same.
can someone advise what to do as many people have advised different solutions for this problem.

777driver

Was anyone ever able to find a definitive cause to this noise (as in the second video above)? I recently bought a 2010 E300 (W212) and while the car is noise free on cold starts or even if shut down for a short duration, i have the exact same “clunking” that occurs for about 3-4 seconds only when the engine has been left idle for about 1-2 hours after being run (water temp indicating between 40-60 degrees C instead of the usual 85deg C).

Thank you for any info....