jeamouse

Got my C300 for about 3 wks. a noticeable clicking sound during driving low speed sometimes even just idle. sound is like some loosing plastic header knocking fast. It is like embedded in the normal engine sound much noticeable in the morning when its is cold start.

I went to the dealer and they told me its normal and it comes with is the new direct inject engine they just used on this model.

To me its not a acceptable answer and I wonder any of you hear the same noise? Or if it is normal as dealer said.

Thanks.

ManiacGT

If this is injector noise then yes its entirely normal. You need to ascertain if its injector noise however. My BMW has this, worse when cold.

Is the noise like a dull ticking noise? Is it louder at the top of the engine, the front, side, etc?

Injector noise is a dull ticking, worse when cold, usually from the top left or right edges where the injectors sit. It can sound a little diesel/idle like. Its also usually most noticeable at idle.

Jinzen

Yup sounds normal. Mine does it so did 2 of the loaners.

floridadriver

I have the same, and have in other cars with direct injection. The C300 has a nice engine!! After break in period, it seems to smooth out some too.

shamgod123

i believe i have the same noise, glad to hear that it smooths out after some time...i park in an indoor parking garage so its more noticeable aftera cold start and driving out

jeamouse

Thanks for reply. its clicking sound but not dull when its is cold start. after warm up (say drive on highway for 10 miles) it become dull and much less noticeable. Its worse when I accelerate. when its idle sometimes its not always there. Funny thing is I can hear it clearly when I shut the door. if I open the door or the hood its too loud that i can not here it clearly.

jeamouse

glad to hear t smooth out after break in, how many mile do you have on it?

jeamouse

It is surprise all cars have it and to be honest it really bothers me. much more than the window noise. its like the cabin is not seal properly that I can hear so much engine noise. I mean other than the clicking sound the engine sounds much louder than the 2014 C300 i've driven. Disappointment if this is normal by design.

jeamouse

Updated: sent car to dealer 2 weeks ago. the guy drove my car and said right away "there is too much noise in this one" So 2 days later called said the rubber seal of the steering column on the "fire wall" is deformed which let engine noise leak into the cabin.

However the part is back ordered in German and there is no ETA. I have been drove a w204 for 2 wks now and don't know how long I will wait.

DerekMB

I have this noise as well , apparently Mercedes is aware of it and there is no fix for it yet .

jeamouse

I saw in a post in this forum mention that the clicking sound is caused by high pressure fuel pump. Mentioned it to the dealer and they act like its impossible

PeteInGilroy

I get a ticking noise when the engine is cold. I only hear it while coasting and off the accelerator. It doesn't last long.

jeamouse

exactly same here. It was worse since the deform seal on steering colloum let the noise leak into the cabin. After they fix that the noise is better but they did nothing to the noise but fix the seal. so I can still hear it. Not sure if it is normal or the high pressure fuel pump has issue.

ManiacGT

Personally I'd just live with it as it could be normal. If something fails, it fails and then its an easy fix. Getting all bothered about something that may be a non issue will just make you miserable. Trust me, on my last car (my Z4) I had it in the workshop so much about small issues it made me nuts. I won't be repeating my mistakes even if the S205 has any issues, which, touch wood, it doesn't presently.

OSMS_Carlsson

We have the C300 and I hear this sound too! Honestly this is really the only thing I dislike about the car...the engine sound of the 4cyl. it sounds almost like a Diesel
Definitely takes some getting use too.
I hope later when we do an exhaust that the sound will change a bit, but the exhaust won't really change how the engine sounds, but just hope to make it a bit more aggressive sounding while driving. The C400 definitely had a smoother engine sound.

Jordyun

I have very similar noise... I was just back from the dealership/service and they said it is the high pressure fuel pump and they insisted that it is normal... Pretty annoying though...

B737NG

I have this ticking noise as well but on my C400. Only while idleing or low power. If I turn the radio up I can't hear it

gfmohn

This is what my C300 sounded like. When the weather turned cold in early Nov., I heard it on starting cold for a few days. When the car warmed up, I no longer heard it. Then the weather turned warm again, and I didn't hear it at all. (My hearing is still very good.) Like yours, my C300 was delivered in early Feb. 2015. It has a little over 5000 miles.

When I took my C300 4MATIC into my dealer to see about several small items, the service foreman and I took the car out on the local expressway to check on wind noise. To the immense credit of my dealer, the foreman heard a faint rattle in the engine. I had heard it only when starting cold. The car had to have the PISTONS replaced! I lost the use of it from Nov. 12 until Dec. 8. (almost a month). The problem is actually a manufacturing defect in the wrist pins. If left unrepaired, it causes premature wear in the cylinder walls.

MASSC300 has found a reference to the MB tech bulletin for this, but the bulletin itself is behind various paywalls. The summary explains the problem. The bulletin is:
When I picked up my car, I told the foreman that I was worried that the mechanic that worked on my car might lack experience on such a big job on such a new model. The foreman laughed and told me not to worry, that they had already repaired MANY examples of this problem! The dealer had had to wait ten days for parts, because they have to compete with cars on the assembly line for parts. MB suppliers cannot make them quickly enough! The foreman did not say whether MBUSA was replacing the wrist pins on new MBs before they are sold. (The defective parts are in engines made before April 20, 2015. [This is the correct information, as corrected on 01/03/05. See note below.])
[Note added 01-03-15: see the comment by deafcon at https://mbworld.org/forums/c-class-w...il#post6612605. So that readers do not have go to deafcon's comment, here is the operative sentence, "Any M274 built at the Infiniti plant in Dechard before serial number ~43000, or built in Germany before roughly serial ~400000 could develop the problem. New wrist pins went into production engines starting April 20th.]

As of Nov. 12, I found two other owners reporting this in MBWorld. (They identified their problem as "wrist pins.") Now there are more. You mentioned two threads where similar problems are reported:
https://mbworld.org/forums/c-class-w...ine-noise.html (the present thread) and
https://mbworld.org/forums/c-class-w...e-startup.html

In addition to these two MBWorld threads, there are other reports at
https://mbworld.org/forums/c-class-w...your-w205.html and
https://mbworld.org/forums/c-class-w...-rattling.html

In addition to the new, 2-liter I4 of the U.S. C300, the engines of following vehicles are also covered in this TSB. The models are: the 2015 Mercedes Benz C180, 2015 Mercedes Benz C200, 2015 Mercedes Benz C220, 2014 Mercedes Benz C250, 2015 Mercedes Benz C250, 2014 Mercedes Benz C300, and 2015 Mercedes Benz C400. I am puzzled why those engines share this defect. The engines of the 2014 Mercedes Benz C300 and the 2015 Mercedes Benz C400 are not new designs. Those models have the older, 3-liter V6 engine. I am not familiar with the engines of the other models.

I hope this does not become as big a problem for MB as The Dreaded Balance Shaft Gear problem that affected certain V6 and V8 engines into MY 2007. My previous 2007 C280 was part of that problem. However, I did not get notice that I was a member of the class-action lawsuit against MBUSA until after I had traded in the car on my current MB.

topsider

Hi which dealer in MA do you go to? I have this problem and would like to have it taken care of eventually, and would rather go to a dealer where they have experience with this

gfmohn

I have sent you a Private Message. Check your Inbox.

bigduke

I have had 3 C3000 cars this past year. 2 were defective and MB replaced them. MB knows they have bad engines and are trying to avoid a recall. This in my opinion is criminal. My local dealer has done over 30 engine overhauls due to the wrist pin issue. I would not buy a C300 and will never buy a MB after this experience. MB USA was the worst part of this problem. They treat you like an idiot and are insulting to say the least. I own 2 MB C300 vehicles and can not wait to trade them in and never buy another MB product.

There should be a recall. I would suggest you listen to your engine at cold start up. You will hear the loud noise when you hit the gas and then let off. It goes away soon after warm up but I wonder what damage is being done to the piston side walls and what will happen later to the motor. Probably burn some serious oil down the road.

My dealer did the best they could but they are at the mercy of MB USA and we were all treated terribly by MB USA.

I have owned many MB vehicles but never again. They are covering up a serious problem.

rustycruiser

From one of the other threads on this issue

A follow up to this. My car has been at the dealer for this issue since Thursday November 27th. The official diagnosis of the engine noise only occurred a week after that on Thursday December 3rd due to weather issues and other work. The Service Adviser called me today to let me know they finally just got the last of the parts in two weeks later, and are waiting for a tool to arrive. So 3 weeks in the shop total so far, with 2 of those waiting for parts. Hopefully they will be able to start the work this week.

I can't lemon this car either, as it was a CPO. It had only 42 miles on it when purchased, so was in essence a brand new CPO.

rustycruiser

And another post

Not so far. I haven't spoken to MBUSA about this yet, and the Service Adviser at the dealer just updates me on the repair every few days. I am not sure if they would offer anything. That is why they have a warranty, to repair issues.

With that said, from my end, I kind of feel like they should. I am not very happy that I am basically getting a partial engine rebuild on an 11 month old car with under 15K miles on it. From my mechanical knowledge, they have to at minimum pull the head and the oil pan to get to the connecting rods on the crank shaft. Then new pistons, rings, connecting rods get installed. What if there is cylinder wall damage? Are they going to just hone them while the motor is in the car? I don't think they will pull the motor for this? And then reassembly of the engine, hoping that the technician does everything 100% correct. Not happy at all.

Mike5215

I've owned a Benz in one form or another for the past ten years, the last three were S Class. Initially, reading your posts, my instinct would be to defend MB and to tell you that your car was a fluke, maybe you're overreacting a little. But researching the car, there are real, multiple problems occurring with high frequency. I would normally tell you to trust the techs to do the work and enjoy the car. Now my advice would be to get a lemon attorney involved and get out of the car. I wouldn't take a free extended warranty, or another 205.

It's great that MB pushed itself to create these beautifully complex and richly appointed interiors, but they neglected the engineering basics and the QC out of Alabama seems uncharacteristically un Benz like.

solarflare

Does this TSB affect all C300 manufactured before mid June 2015? If so, I need to pay more attention to this.

Mine is a September 2014 build.