Well its fixed.. Put my third belt tensioner on but this time an original equipment one. Vibration is now gone. I guess I would have never thought that the ebay ones I bought wouldn't work. Live and learn.

Thanks for all the help!!!

It was not doing it when I purchased. Yes I am brake torqueing vehicle to hear this at 1100rpms. Serpentine belt is new!! Is their a difference in belt tensioners off of ebay compared to an OE tensioner?? I will check mounts and pulleys again. Thanks for everyones time!!

I owned car for 6 months.. Vibration was there before motor mount was replaced.. the noise is definately a vibration that only happens at 1100 rpms any higher or lower and its not present.. I took it to a shop at they checked all pulleys. Today when i took belt off it did not do it when I started ca...

And I Have searched!! Vibration in "D" and "R" only at around 1100rpms. Replaced the belt tensioner twice with ebay ones.. Then thought it was alternator, but after replacing with a new one no change!! Does not vibrate with belt off!! Should I buy an OE replacement tensioner and ...