Hi, I have a problem for the first time with my C230 kompressor coupe, I would appreciate any help.

A couple weeks ago we started to notice that my engine is louder and noisier when idling. A couple people pointed out that it's noisy. Kind of reminds me of a diesel.

So the other night the car started sputtering while I was driving home, and shaking as if it was going to stall. It was enough that every passenger could feel the shaking. The check engine light was on. It wasn't just when stopped, it was doing it at any speed. But it didn't do it the next day.

My dad brought it to the dealership, and they said it was because we used regular octane gas. The car has *never* had anything but premium in it, so they are just wrong. They suggested that a gas station may have put regular in the premium pumps. Even if there was regular octane, I don't think it would do that.

I think it's connected with the engine being noisier lately.

Does anybody have any idea what it might be?

Thank you!

 

Got a similar problem, several times when I start my car and it is idling, the car seems to be struggling and even just sitting there not applying any gas the RPMs go up and down just a little and the car will make a sound as if it was going to stall. I am lost.

 

Could be all sorts of things. The dealer COULD be right...it COULD also be totally incorrect.

So why did the dealer say it was due to use of low grade oil? What evidence e.g. Diagnostic Fault Code DTC lead them to this conclusion.

If the CEL is ON it is ON for a reason. What does the code state or what is the code?

What octane (or RON) is your domestic low grade fuel (this should be on the pump)?
What octane does your handbook state is the minimum SAFE grade fuel that can be used in your motor? Engines in different territories can tolerate different levels of low grade fuel.

Stuart

 

Well as I said, I never use anything but the highest octance fuel that is available here. I think the highest is 91, which I always use. The lowest here is 87.

The dealership did not explain their reasoning for telling us this was the problem, and I don't know what fault codes they read. I assumed they were just guessing because of the symptoms that were described.

I was thinking that maybe the experienced people here may have heard of such a problem on this engine, it could be a common fault or something that the dealer didn't want us to know about.

Also although I know the gas was of a good octane rating, does anyone suspect contaminated gas, or moisture in the gas, could cause this behavior?