2008 - Burning plastic smell, scraping sound idle, goes away under power, no CEL

[AgentMull]

So the other day I noticed the soul crushing smell of burning plastic after stopping at a stop light at the end of a highway exit ramp. I thought it was another car since I didn't notice anything odd going on with my car. After that moment I've had a scraping sound during idling, mostly when I first turn the car on while cold, but it does come back every once in a while at a light. So far there has been no performance loss or any noticeable difference while driving. I am due for an oil change, so hopefully a cursory inspection can detect the problem, but I wanted to know of there is precedent for this kind of problem. Thanks!