I've had this problem with my 2000 Sable with the vulcan for a while but it has gotten worse lately. There is a rattling coming from the lower part of the engine on the passengers side. It sounds like its just behind the glove box. It makes my engine sound awful I hate this sound and I have no idea what it is. The car doesn't have to be under heavy acceleration, it just always happens at around 4k rpm. Any ideas?