alternator fluttering noise, not chain slap?
 

I started another thread on what I thought was chain slap on a car that had the timing chain, tensioners, rails changes 2 years ago and 6000 miles. I now wonder if it is not the alternator. I heard something that almost sounded like something switchinf on and off on the car followed by a fluttering sound that reminded me of chain slap. Can an old alternator make a sound like that? will it often do it when cold? I am probably changing this relatively new tensioner myself anyway. I put some mobil one 10w 30 in there to thin it out, had 20w 50. Perhaps the existing tensioner willlike this lighter weight oil.