SimonOHC

Hi all,
I am new with Mercedes and would most appreciate any assistance.

The problem is my C200K (Auto) rpm drops to a level (still above 500pm) where I can feel the engine /steering wheel vibrates (feels like engine dying but never died once so far) whenever I slow down to less than 10kmh, what could be wrong?
I have cleaned the idle valve, re-programmed as well tried with either C or S mode.
Other the above, everything works fine on the move.
Any assistance/sharing on this experience greatly appreciated.

Thank you

Peabody

How many miles are on the car, and what kind of gas are you using?

SimonOHC

Hi Peabody, thanks for the response. The mileage is only 44k km and I use 95 Octane fuel

Sportstick

Isn't there an electronic idle stabilizer, which would not be susceptible to cleaning, etc. if it has become faulty? I think it's time for a diagnostic plug-in at the dealer!

C300Sport

What is your idle RPM supposed to be? If it is running below that, I agree with Sportstick that your engine electronics are likely the culprit with a faulty sensor being the most likely cause.

Peabody

If you're still under warranty I'd let the dealership plug it in and diagnose it. If not, you can start with some Sea Foam and replacing your air filters (due at 50k right?) if you haven't already. If that doesn't work, then you're going to the mechanic regardless.

amdeutsch

I don't believe you are using the right fuel. In your country they should have higher rated fuels, 98 or above.

Peabody

95 should be what is recommended by Mercedes.. It might not hurt to fill up on a tank of Shell Power-V, which country is the op in? I would always go with the highest rated if he's in Eastern Europe.

Royce118

I'm running on 95 here in Brunei Darussalam. Unfortunately that's the highest grade of fuel we have here..

SimonOHC

Dear all, thanks for the feedback and suggestions, most appreciate it.

Unfortunately, an engine diagnosis revealed no fault. I have tried 97 Octane fuel, still no difference. Air filter had been changed too. The RPM on idle is around 700-800 with the aircon and lights on. It is only when I slow down say to a junction that I get the symptons.

Could it be foul plugs? Gearbox? The mechanic had also checked the engine mountings and they are ok. He suggested that it could be a loose/worn alternative bearing taking an extra load.

Any one had these symptons before?

Thanks to all in advance.

kevinwithdabenz

why not take it to the dealer?

Sully

Have you checked the water level in the radiator? Also ensure that the thermostat is not sticking. You'll have to get a mechanic to look at that for you.

morph860

When you changed the air filter, did you put the cover back on right? I had the same issue when I installed my K&N. I didn't push the backside of the cover back on all the way and was getting a weird idle. You should have a white metal clamp that needs to be popped back on to hold everything on tightly.

SimonOHC

Thanks all, I will check all these and revert and share once I have the problems resolved.

Peabody

If all else fails, Seafoam. That stuff is magic in a can for these kinds of problems.