akbro93704

Ive posted about this before, but it seems as of late, my engine has been getting more gritty feeling. Thats the best way I can explain it. It was whisper smooth when the car was new, but now it seems like when I'm accelerating, I can FEEL the engine. Slight vibrations through the gas pedal and steering wheel. It seems most obvious at around 2000 rpm's. I am going to take my car in when I have time, but has anyone else had/have this problem??

Also, it seems the car is pulling to the right a lot more lately too.

Aggressive

OMG!! I have had a problem like this but it is extremely noticable. It scared me so much one time that I thought the Tranny was slipping or a gear was not grabbing in the tranny. I had my car flat bedded to the dealer. They found nothing. I drove the car all day yesterday, over 100 miles, and it did this all day. I then had an appointment with the dealer(for the second time), as soon as the master tech drove the car with me, the probelm went away. They told me there are no codes are being thrown out to set off the check engine light so they have no basis to start on. I have been into cars for years and this completely boggles my mind as to what it is. The solution they told me to try was running 89 octane gas as well as some dry gas incase or moisture. This made no change. It even seems to me that the car does not have as much power when it happens. It can be intermitent or happen all day. Any ideas??

akbro93704

What does yours feel like exactly? It just seems like I can feel the engine too much through the gas pedal and car. These engines should be completely smooth, and mine was when I first got it.

Glyn M Ruck

The pulling to the right is common once tyres have bedded in. They must set the alignment with one degree more castor on the right than the left to counteract road camber and the influence it has on tyre wear. The opposite applies to RHD cars

Aggressive

Mine is intermitent. Some times its smooth like it was when new and other times its extremely rough. My exhaust tone changes big time almost like I have cut outs in the exhaust. I can feel the roughness through the gas pedal too. The power gets less and it brings be to think that the tranny is slipping. I feel like I really need to take the car in again and tell them I don't want it back till its fixed. If they do not fix it, the problem seems bad enough to me that it will damage something badly. I haven't driven the car in 2 days becasue I am so aggrevated with it.

C300Kid

hmm...thats really weird. i hope mine doesnt do this...

akbro93704

Yours seems worse than mine, but hopefully mine doesn't progress any further. I would definitely take your car in!

Glyn M Ruck

Get them to check the engine mountings

johff

Same problem I have with my C 300 4 MATIC....noisy, rough and vibrates a lot. I brought my car in and they told me that it is perfect fine

It sounds rough and "gruffy" when the engine is running at 1500rpm or when the car is going at 45mph...

C300Sport

I agree that it sounds like the mounts. Do we have "active" mounts on the C Class?

Will617

I had a similar problem with my Mustang GT a few years ago. After several trips to the dealer it ended up being a clogged catalytic converter.

C300Sport

So I guess the roughness would be from the backpressure not allowing all the cylinders to intake/exhaust evenly??

Glyn M Ruck

I'm not sure what you mean by "active" mounts. Terminology varies around the globe. You have fluid filled mounts. Cat should be OK at these mileages.

johff

I am quite dissapointed. MB could spent so much time, money and resources into safety, engineering and refinement and this is one area that is really lacking in refinement.

I don't my expect my car engine and/or exhaust to vibrate or shake when the car is first started from stone cold.

In addition, this is one area that you hear, feel and sense every second as long as your foot is on the accelerator. How can MB put so little resources into the engine, exhaust, etc. and lack in refinemenet? I really wonder .

My car exhaust tone changes from time to time and it sounds inconsistent. Most of the time, it sounds rough or sounds like I have a loose exhaust somewhere that send a lot of noise, vibration through the steering wheel, accelerator and even the seat.

I still can't believe that they either ignore the issue or just can't solve the problem due to a permanent design fault somehere that they can't find.

I mean if you look at the new C-Class, it is such a "complete" vehicle and yet this one issue really ruins the feel of the engineering of the car or just makes the car feel "incomplete".

akbro93704

I completely agree!! Its very disappointing. The old C230 V6's were very smooth and quiet (from having them as loaners)...why should the new design be worse?

Question---anyone with C350's have the same problem?

Glyn M Ruck

The car should not do this - There is something wrong with your car

C300Sport

Several manufacturers have used differing systems to vary the stiffness of the mounts in response to engine load and rpm. The idea is to have the mounts "tuned" to allow the least amount of NVH. Only ones I ever had were on a Nissan Maxima and that was a pretty nice powertrain...especially for its day...

Glyn M Ruck

I'm with you - I forgot about the Maxima. I had one when I worked in Dallas a number of years back and you are correct - It had active mounts or dynamic mounts we call them on this side of the pond. A very smooth affair.

johff

Funny enough is that the only time I don't hear, sense and feel those "yugo" roughness is when I am really aggressive with my acceleration with the engine running up to 3,600 rpm and speed up to 75 mph. But not very often I can do that. And yet, this not what this car is really about, running the engine at 3,600 rpm every time. A Merc is still a Merc that it is still about comfort and prestige. Also, I value my driver licence.

So, I am not alone with this issues. I hope there is a TSB coming out soon so that I can bring the car back to dealer to have the issue resolved...

Glyn M Ruck

You have every right to expect a plush ride. My C240 only has 47,000 Kms on the clock & it's smooth as silk. The W204 is even better.

akbro93704

The weird this is, my car is smooth at idle. It's just when you press on the accelerator, theres a little too much roughness.

Aggressive

Sorry to hear your have a problem too. The good part is the at least it seems to be a developing common problem. "Gruffy" sounds like a perfect word for it. I was thinking of trying to video this and see if the camera picks up on the sounds. The thing is that the car only has the problem when it wants, other times its perfectly smooth like it should be .

johff

It appears we are on the same boat with this issue...can't do much unless we can figure out the problem ourselves and direct that specific issue to the dealer to address.

Glyn M Ruck

A few questions. Is this grittiness evident if you just rev up the engine - Not in Drive? - Is the frequency of the vibration, in your opinion, engine speed or RPM related?

I still think the likely causes are engine mounts or something touching something that should not. Causing transmission of vibration

The power loss/exhaust note change has me baffled - This can be a piece of the CAT honeycomb breaking off & moving around but at low mileage this is unlikely. - A wonky CPS can also cause this because the engine does not know accurately when it is at TDC - also unlikely at low mileage although infant mortality syndrome has to be considered with electronics. CPS failure or deterioration usually leads to hard starting though.

It can't be fuel feed related or you would throw fuel trim codes. It can't be plugs or coilpacks or you would throw misfire codes

akbro93704

I only feel it in Drive. If I have the car in park/neutral, there's no out of the ordinary vibrations coming from the engine. I can't feel vibration in the pedal at all. Once the revs climb past 4500 or so in P/N, then I can start to feel slight vibrations, but that's normal.

When in Drive, I notice the vibrations right off idle to about 3000 rpm, give or take a few hundred. It's not really a steady vibration either, it's "crunchy" or "gritty", if that makes sense. I can also feel it when just coasting at city speeds too. It's not some terrible vibration, but its enough to be annoying.