M104 Extremely Rough with Raspy Whistle

[croftynsteph]

Hi all
So the 300 is being a bit of a *****. Periodically over the past four days the engine has idled extremely roughly throughout the RPM range. Putting the engine in Park alleviates the symptoms slightly but not completely. The car idles so roughly it feels like it bounces when you step on the gas. This is accompanied by a loud raspy whistling sound that had started in the rear a week ago when going over bumps (I assumed something was rubbing and planned on looking at it over the weekend). Now, the whistling sounds as though it is coming from the front driver's side area. I'm unsure if it was something in the fuel line that worked its way to the front and is now clogging an injector or the distributor etc. Any help, as always, is appreciated.