It is especially around 1500 rpm when the car is coasting at 45mph, I could hear, feel and sense the "gritty" and "rumbling" noise and vibration. My car is a C 300 4 MATIC luxury. If I want any "gritty" and "rumbling" noises, I would have gone for an AMG model. This is not what I expect in a "normal" engine in a model for my car. In summary, it is just disappointing and aggravating.

Mercedes can make a car with cornering foglights and all other safety and engineering features that you can dream of. Yet, this is one important area that they failed to "master" properly. Lexus really puts Mercedes to shame in the refinement of this area. Let's be honest and not lie to ourselves just because we are loyal Mercedes fans!

My advise to Mercedes is stop making too many models; thus, allowing or giving the engineers more time and resources to execute properly and resolve any faults before the car is gone into production. I believe that the engineers must be over stretched with too many models on their plates that Mercedes don't need

[QUOTE=akbro93704;3190102]Ive posted about this before, but it seems as of late, my engine has been getting more gritty feeling.

It is about time we had a MB techs answer to this problem. You blokes keep whining & whinging but do FA about it.

[QUOTE=Carsy;3196751]Agreed! - Listen guys - Johff - I took a family member's C280 Elegance for a run this weekend - what you know as a C300 Luxury - and it is utterly smooth - no vibrations or noises so it's not a design problem, if it was a design problem all cars would do it & they don't it is a fault on your cars that needs to be diagnosed. This was obviously a South African built car I drove. I'm very sensitive to such things. I changed the tyres on my car at only 15,000 Kms to Michelin Pilot Exalto PE2s to get away from such nonesense. This car has no inherent NVH problems & is just as smooth as a Lexus.

With vibration only in drive & only when moving it brings other things into play. You are applying torque to things so it could still be engine mounting etc but could also be the transmission or even feathered tyres which feels & sounds like a failing wheel bearing & puts vibration into the car at varying speeds & makes rumbling noises. You would swear something was about to fail. Are your cars fitted with Continental SC tyres. This is typical of them & gets worse as they wear. They are junk from an NVH perspective.

The time has come for you to give your dealers hell until they diagnose what is wrong. Everyone needs to be open minded about this because it could be something as stupid as tyres. Conti's vibrate just as you pull away, make noises & vibrate through the controls at varying speed, rumble, & vibrate in low speed cornering.

Carsy - see you drive a diesel - do you have any such issues?

[QUOTE=Glyn M Ruck;3196857]Absolutely not. This is the tightest, smoothest quietest car 4 cyl I have driven. My only observation is that there is a slight " labouring noise" but no vibration when the car is driven on the flat at 60km/Hr . The 5 speed auto is in 4th with RPM at 1200 . Our European Forum member says that there is a software upgrade that will fix it. I am slack in not taking it back to the dealer as everything else is fine.

[QUOTE=Carsy;3196870]The new 7G software makes a big difference

And the logical conclusion of this is that whatever model you would want to buy is one of those they stop building, to concentrate on .... what?

Any car company has to have a fairly diverse product line in order to meet customer demand. Okay, well, we don't see the A or B class cars in the US, but other parts of the world do. One key to building solid cars is reuse. If the parts can be shared, they should be. That goes for engines as well as license frames. Mercedes does that fairly well.

I would agree that there are too many SUV-like vehicles, but customer demand has required that to be.

As we should all realize, giving engineers "time to do the job right" is probably code for never, ever, completing the job. Meticulous engineers will continually fiddle the bits until the company's out of cash, and the product still won't be customer-ready. Let's just be happy with what we do get!

My car has the rough feel & throaty exhaust when started cold in the morning before the motor goes into closed loop too. It only last for about a minute and then settles and smooths out. I wouldn't worry too much about it, I think it's something you will find on almost all newer (powerful) cars. My '08 Nissan Frontier with a 4.0L V6 does the same thing, engine is real coarse & rough, stock exhaust system real mean & nasty sounding for the first two minutes then settles out nice & silky smooth once in closed loop and the motor is warm. My gripe is that my 7-Gtronic sometimes feels like it in between two gears at times, example I come home, pull into the driveway and if I slowly roll up the curb and the rear wheels are still on the bump the trans will jerk violently. It will sometimes do this when slowing down for a traffic light, but the light turns green as you are slowing but you don't stop. If I put my foot back on the throttle slowly I will get a kick or jerk from the trans likeit didn't have the right gear or something it's really annoying, I'm so worried about it that as much as I love my car I might have to part with it shortly after the warranty expires. It's a shame because I really love the way it looks and drives 95% of the time, and it's the first car I ordered & picked out exactly how I wanted it from interior color to exterior wheels & options.

-Ryan

These guys cars are not only doing this at cold start.

Re your 7G - have the latest software loaded. The only time you should ever get a jerk is if you catch the transmission just as the torque converter is locking up. This usually happens due to clumsy driving. This is common to all Benz autos - 5 & 7 speed. It's certainly not transmission life threatening.

I want to confirm that I only feel this in drive also. I have been in park and rev the engine with no problems. If you remember, I was aggervated and did not drive the car for 2 days. Well the problem occured when I drove from the start out of my street , calmed down and has not happend since. This is the mystery of this situation since the problem comes and goes. I switched to 89 octane like the MB tech told me to. I also added a bottle of dry gas. I am on my second tank of 89 Octane and have not had any problems yet.(FYI: I was running 93 octane) I feel it very hard to belive that the gas was the problem or that there was moisture causing this. The car sounded really bad and fuel could not have done this. I think it could be the slim chance of a clogged cat or a slipping tranny or what ever else drives the 4-matic system.

[QUOTE=Glyn M Ruck;3196857]The tough part is, I have had my car to the dealer. The first time this happend it scared me so much that I called MB road side and they flat bedded it to the dealer.......they found nothing. I took it in again, the car was haveing the problem all day, roungh starts, gruffy engine tone, less power, not smooth like it is when the car drives like a dream. Guess what, the tech drove the car with me, nothing........The car had the symptoms when I got off the exit to go to the dealer and 10 min later it was not doing it for the MB tech. This is why I finally wanted to see if anyone else had a problem.

Is any one else with the problem willing to try the bottle of dry gas and 89 octane? Follow the directions on the bottle, its usually good for only 15 gallons.

You must run on premium gas

I wonder if the "gruffy" or "rumbling" engine tone could be due to spark plug issues? Ironically, the engine runs a lot smoother when it is cold. Once the engine reahes its normal operating temperaturs, the tone changes to gruffy.

Mr car engine was smooth yesterday until I drove it on the highway. It was a real joy driving a "smooth" Mercedes until I drove the car on the highway. Once I was off the highway and back to city driving, the engine tone was rough and gruffy. I wonder if it is temperature related. There must be something that the engine doesn't like when it gets too hot? Spark plug related? Exhaust related? Catalytic Converter related? Typical M272 engine sound?

I don't thnk it is has anything to do wth the engine mounts. If you have a bad engine mounts, the engine should be consistently rough all the time.

Have you ever driven another M272 engine? The 2.5 V6 in the '06-'07 C230 was very smooth and quiet, no undue roughness or sounds at all. To me it was the smoothest out of the M272 engines. Our ML350 and E350 are also smooth when accelerating. Whats weird is my C300 is smoother at idle than the E and ML, just rougher when accelerating. :nix:

This is my first M272 engine powered Mercedes. I am still not convinced that the engine should be this rough. It should be smooth and quiet. Excuse my language, it is totally a piece of crap!

It absolutely shouldnt be rough. I'm going to take my car in when I have time over Christmas break. Because honestly its the only thing detracting from the "Mercedes"-ness of the car.

I hate to hear that the engine is totally ruining your MB experience. There is no doubt that something is not operating properly with your engine so I would say to have the dealer work hard to fix it. I know it is not what you expected from a Benz, but when they do find the problem, they will either have to fix it or cover you with your state's Lemon Law.

Whinging on this forum is not going to fix your car. Whinging at the dealer & MBUSA is.

The roughness you describe is not typical of these cars so do something about it!

Well........the MB Master Technician at the dealer told me to run 89 octane, His exact quote, "Thats what this car is designed to run on." Gas mileage is exactly the same and the car feels smoother aside from my intermittent gruffy, clooged cat/ spark plugs/ slipping tranny/ "whatever it is" problem. You are right Glyn.....Gruffy is not what this car should normally do.

These cars are designed to run on 95 Octane Eurograde.

No more comments!

IMPORTANT UPDATE!!!!!
 

Hey guys, I took the C300 back to the dealer for the 3rd time on Thursday the 11th. Good news! I am not crazy and they found a problem. The service attendant, the Master Technician, and one other person drove my car. They all heard and felt the problems that I have been having. They could not believe how bad it was. The result............They still have may car, its Sunday the 14th........They have ordered new Motor Mounts and a new exhaust. I do not know the details but they said there was something wrong with the Motor mounts and they believe I also had a leak in the exhaust. I will be starting a new thread with my new found problem. Thank you all for your input.

This comes as no surprise. Keep us informed. I really hope you end up with the smooth car you deserve.

Congrats on finally having them find your problem...it is amazingly frustrating when your car refuses to act up when at the mechanic but does it all the time for you...:D

Finally! Let us know how it drives when you pick it up :)

Any news on the repairs?