raspu

try engine bearing eather top or bottom....dealer claims the oil changing will not help, claim they put wrong bearing at factory

raspu

Keep bugging the dealer....tell him how much you hate your car and to look at the top and bottom engine bearing....if nothing is wrong ask for documentation of your visits for when this thing blows up you can address this matter in court. document document

jsc300

Just wanted to give everyone an update. Took it to the dealer and i left it there, went back started it my self and the tech heard the sound. The dealer sent a recording of it to MB and they told them to replace the crankshaft bearings with larger ones to eat up the gap. got the car back yesterday so I'll let you all know if it repeats is self again.

Pretty much was rod knock. The bearings can be swapped from underneath by dropping the pan. I guess I got a free oil change out of it.

raspu

problem corrected...not only a free oil change but tranny fluid, new gaskets and bolts....ladies and gents the answer is oversize bearings that are accessible thru the bottom of the engine, my car was at the dealer for 9 days and the problem is solved..ps make sure they do the transmission software upgrade in order to do away with the transmission delay while changing gears

krazn1

excuse my ignorance on this topic. I tried following it for the past 4 pages, but i dont know what sounds u are talking about.

is it similar to this noise?


cause mine makes this noise, and its kinda freaking me out.

earlybird

No. The engine noise that is being discussed in this thread lasts for only a few seconds on start up.

krazn1

ahhhh...thanks for the video. yeah..i dont have that, wow thats annoying. at least that's only for a few seconds. mine is a constant ticking. i think i have the infamous purge valve.

raspu

RASPU; GENTLEMEN THAT IS THE SOUND... THE CURE IS OVERSIZE BEARINGS
MY CAR A C-300 BENZ HAD IT DONE BY THE DEALER AND IT TOOK THEM 8-9 DAYS TOLERANCE INADEQUATE W/8429 PERFORMED NOISE LOCATION TEST ORDER TO DETERMINE LOCATION, FOUND COMING FROM LOWER END, FOUND NEEDING CRANK BEARING REPLACEMENT

raspu

THIS IS SOMETHING ELSE...DOES NOT SOUND GOOD.

raspu

ENGINE BEARINGS, TOLERANCE INADEQUATE W/8429 ...REPLACE ENGINE CRANK BEARINGS AND INCREASED SIZE AS PER SHEET.NOISE COMING FROM LOWER END, MUST PERFORMED NOISE LOCATION TEST, 8-9 DAYS AT DEALER. GOOD AS NEW

raspu

LEAVE THEM YOUR CAR... ASK THE DEALER ABOUT W/8429 CRANK BEARING REPLACEMENT, COMING FROM LOWER END NEEDS CRANK BEARINGS REPLACED WITH AND INCREASED SIZE AS PER SHEET... QUOTE FROM MERCEDES BENZ WORK SHEET.. I WAS READY TO RETURN CAR 09 C300 WITH 40000 K CERTIFIED VEHICLE IF UNABLE TO FIX. EXCELLENT DEALER

Robmir

Hello Raspu

My 2009 C300 is having the same noise cold start issue.Still have a few months of factory warranty left. I see in your profile Miami .I'm located here in South Florida too..to what MB dealer do you take it for the fix ? planning to take mine to the same dealer as yours... Thanks !

Moto_Guzzi

Damn, that is the noise at startup I was talking about. Myne was quiete for a time but came back. Cold or warm. It going for a very long time, nothing broken yet.....77 000Km. Got clean bill of health after EISH was replaced(2-weeks at dealer).

I hate a MERC engine sounding like the old Ford V6's at startup.Must say this was a Merc disappointment for me, although I liked the car.

Thinking about what I should do, still in full guarantee(Extended).

Acapulco Bill

One wonders if you should just leave it alone. From most comments, MB dealers service departments leave a lot to be desired. Imagine pulling the engine (not sure if this can be done from below), opening the crankcase, undoing all the rods, removing anything driven by the front of the crankshaft, pulling the crankshaft...

After THAT, swapping the bearings, installing the crankshaft and all the stuff that it rotates, reconnecting the rods, and torquing everything up to factory spec, closing up the engine and seals in "clean room" conditions, and reinstalling the engine with all that entails?

And one expects that after all THAT, the C300 engine will be BETTER OFF than before? No way, IMO. If your W204 has taken you 80k miles already, most likely it will go another 80k.

I am thankful that my C300 engine is SO QUIET on startup, I have the habit of lowering the window just to make sure. There are bigger issues with the life and reliability of the W204, and that affect the driver's pleasure every mile, like the LAME 7G TRANSMISSION, 4Matic problems, starter switch and electrical issues. Recommend enjoying your C300 just as it is, get other issues resolved while still in warranty.

Moto_Guzzi

My windows are always closed, I hear it in the cabin if radio is not on.
I noticed the other day at dealership, they may not hear it well with building general noise, but in my garage I hear it clearly, as well as away at parkings.

I think I started hearing it around the 20 000km service, around there.

I have a mazda which started a noise(Rocker-type of a noise, not tappet, not bearing) at new 7 000km. It still runs at 259 000Km, nothing seized or broken.

Lets see what the dealer say, I logged a complaint, asked them to get the facts from factory engineers about this.
I always said to myself, no..not a Ford, please!!!.

Moto_Guzzi

Bottom end knocks upon startup:read this...
http://www.justanswer.com/mercedes/5...n-startup.html

Answer, parts of it......
Hi, I think I am familiar with the noise you are referring to if it is a knock on initial start up that lasts a couple of seconds. The noise is characteristic of the M272 motor. I believe it comes from the timing chain system. Mercedes has not deemed it to be a problem and there are no service bulletins on the matter.

eurotec : You might try going to a 5W40 motor oil if you are using 0W30 or 0W40 currently.

eurotec : I do not believe that it is a rod bearing noise and the main bearings would not cause a noise like that.



The variable valve timing mechanisms can knock on initial start up. That is where I think the noise comes from. I do not think the rod bearings would only be noisy on start up. If you had a clearance issue you would also have the noise when you tromp the accelerator.

I think the reason is that Mercedes factory does not or has not seen this to be a problem. I can tell you that I have heard the noise on a lot of the M272 motors. I think it has more to do with the light oil and the valve timing mechanisms than it does the bearings. Knocks from the VVT are not unusual on vehicles that use the system.

I agree that something should be put in writing. Even if they simply explain the noise. They problem is that most likely they probably don't have a field repair fix for it.

Yes I think that there is a very good chance that if you replaced the vvt mechanisms you would quiet the noise. It's also a very costly proposition to do so.

Acapulco Bill

So only the bottom bearing is replaced? That may take out the slack, but it will also cause excess stress and wear on the very center of the top bearing. Will post a picture of this engineering problem later.

johngelone

Yes our E240 140Ks on the clock does that at odd times, so am please to hear that is a common noise.

BenzDogg716

Hey gang- I've git the same 3-5 sec knock when starting up cold but car runs fine other than that. I just had the 20k service done and I'm wondering if they replace the stated crank bearings during that service. I wouldn't think they would go that far for a standard B service but I didn't notice the noise before that. Also- what should I expect to pay to swap out the bearings to the larger size if I feel so inclined? Thanks

Jackrattenbury

new member here. My c300 started making loud tapping sounds on cold start up after just 2,000 miles. It lasted for about five minutes then went away. It was more pronounced when I took my foot off the gas pedal. Dealer checked it and on advice from factory changed oil and filter. They found debris. Problem persisted. Factory said it would take 6 weeks to discover a fix but it was fine to keep driving until then. Apparently they needed to wait for parts. Eventually dealer replaced pistons, con rods and shell bearings. I visited the shop while it was in process and the entire engine was out and completely disassembled. My confidence in the motor is shattered! I complained to MB that possible long-term damage may have occurred to the cylinders and wanted an extension on warranty. They have offered to increase an extra year and up to 75,000 miles. I've put another 1,000 miles on it since the fix and so far so good. No more tapping but I am surprised at how noisy the engine is in general though.

P1NKST@FF

Has anybody just left the noise alone and made it to higher mileage, or tryed a heavier cold weight oil? The idea of the car knocking has me worried but I want to believe mb wouldn't put wrong spec bearings in their engines and expect them to be fine. I tend to believe that the noise isn't the end of the world since I've heard older small blocks make far worse noises and be fine for miles and miles but I'm not sure I can afford to rebuild this engine and don't want to tackle it in my garage

cvx5832

I did. Our C300 made that noise at 9 miles. It continues to make that noise today at 112,500 miles.

I think you'll be fine.

P1NKST@FF

Sweet thank you