JasminChicago30

08 c300, has this rough noice when is on af low idle, and when is in the park and neutral the idle works fine, but when i put it in drive the rpm goes down alittle and vibrates, same thing when i come to a stop the car vibrates and the rpm goes down thats when the vibration happens, i noticed it when is more colder outside it vibrates more than on a nice day, any suggestions? Could that be the Engine mounts?

chrisridebike8

Sounds like motor mounts.

timlippold

Could be motor mounts or front axle. Mine does it but not bad enough to warrant an investment.

retna7

M273 engine misfires at idle.

Replaced:

Ignition Coils 2019
Spark Plugs 2019

Camshaft Adjusters 2022
Fuel Pump 2022
Fuel Filter 2022
Intake Manifold Gasket 2022
Decarboned Intake 2022
Fuel Injectors 2022
Knock Sensors 2022
PCV Vent Valve 2022
Motor Mounts 2022
Transmission Mount 2022

Air Pump Control Valves 2024
Oil Centrifuge (Drip Pan) 2024
PCV Oil Separator 2024


No codes and drives well outside idle with a cold start. Idle seems fine once warm.

Cleaned the MAF but may need to be replaced.

Could be OE Tune affecting timing so I'll be contacting customer service for removal instructions.

Have no idea what else it could be:

Cold start after a few days: