2005 Mazda 6i Rattling Noise
So today I was driving on my way to get my tires fixed when I started to notice a rattling noise from my engine. I only drove with the noise for about 10 minutes until I arrived at Sears. I asked them if they had any suggestions on what the noise can be and since I was overdue on an oil change they thought it could've been from the bad oil. I got the oil change done and as soon as I started driving I heard the rattling noise once again. I will say, I had my alternator changed about a week ago and a new wire put in and the car was running fine up until today. I haven't noticed any significant problems with the actual way it was running but the noise is very loud and alarming. I couldn't imagine needing to use a higher octane gas because it runs on regular fuel. It is a 2005 Mazda 6i 2.3L Automatic. Does anyone have any suggestions on what could be the source of this noise I'm hearing?