ign92

Lately I've been feeling this raspy, very light but definitely there and different than about a little over a week ago, noise whenever I accelerate my 08 C300.

The exhaust noise is a bit weaker and different than before as well.

I'm not sure if I can describe it as a noise but more of feedback on my foot when pressing down on the pedal, slow acceleration, and raspy feeling on it.

Not sure what is going on. I do remember that I accidentally switched the car to manual shift mode without noticing and managed to accelerate a bit too much on 1st gear before realizing what was going on.

Is that bad?

Will I have to unload $8k on a new transmission?

Maybe I need a new set of tires, thread looks fine.

Flawed

I get the same thing on my '08 C300. Did you just purchase it recently?

I noticed my car started sounding different from when I purchased it from the dealer after about a month (note I don't drive it often). I always just assumed they ran some garbage cleaner through the engine or fuel to make it sound better and it eventually wore off.

What you are describing kind of sounds like you switched the car from sport mode to cruise mode. Try hitting the "C/S' button under shifter.

Cruise mode: Starts car in second gear. Less responsive pedal.
Sport mode: Tightens suspension. More responsive pedal.

And as for the switching to manual mode. Don't be afraid of it, I use it often, have fun with it. Pull knob left once to engage it, hold right to go back to automatic. Left once down shift/ right once upshift.

ign92

I've had it for almost 5 months now, and just recently noticed the change. Hitting 60k miles soon. I know the C/S mode is not it, because even S feels a bit laggy now and raspy with pressing down the gas, although S still feels a whole lot smoother than C. But before S felt like the car was flying compared to C and now they are a whole lot even.

I'm reading some stuff about some accelerator reset, will try and see what I get. Maybe it has to do with change of driving styles since I just changed jobs from a 5 minute sprinting at 40-60 on the highway to 45 mins of gas and stop traffic commute. Maybe that messed with the behavior of the gearbox.

I just hope is nothing serious.

Flawed

I hope it's nothing serious.

I know the feeling, sometimes my car feels a bit sluggish as well. I think it might just be do to the fact that we expect it to be ready to win a race after just starting the car up cold.

I was just outside a few minutes ago working on some of the lighting and kept the car on for maybe 20-40 minutes. Needed a new bulb and took it out for a drive.

And it felt amazing. The car was flying. I even thought the whole time how weird it was because I couldn't remember when the last time the car ran this good.

I only commute about 10 minutes a day. So most of my time spent driving the car is off sluggish cold starts. Normally when I start it off cold I'll notice the car is a bit wobbly. And I thought the tire pressures where off and I checked them a few times but they always came out okay (sometimes a little off but not by much. It slowly get's better until it feels normal again after sometime of driving around.

I also remember that when I had a bike, you would have to let it run a bit before driving. Otherwise letting off on the throttle would stall the bike. I don't know much about engines/transmissions/etc but I am sure that there is some correlation to that story and our cars.

Maybe someone else here can put some reassuring feedback on the issue.

If you are worried you rev'ed it too high in 1st gear by accident as you mentioned before, then don't be, there is a built in safety feature that will automatically upshift/downshift if you are rev'ing the hell out of the engine to an unsafe point. It being a Benz, I'm sure that safety zone is pretty big, lol.

ign92

Well that gets that worry out of the way then. I did do the acceleration reset thing (key in first position, push down pedal, turn back key, hold for a few seconds, release) and took it out for a spin, noticed a difference, maybe is placebo.