My friend has a 2003 Dodge Neon that lately has been shuddering, and one time even ceased. I've noticed the shudders only at idle (after it has just been started up, at a stop light, etc), however it's "bucked" a few times when going 30 or 40mph. After a talking with my father, he suggested that it could be the spark plugs, or the timing belt. I figured that I might as well ask here before I go and get charged by a mechanic to tell me something I might have been able to find out on my own. Does anyone know what could possibly be causing this?
Thanks to all in advance! All input is appreciated.