Why is my ps3 fan so loud after doing the YLOD fix

I just tore my ps3 apart and ordered your kit to fix the YLOD "yellow light of death", I followed the intructions on your site to fix it and put it back together, and it works when I go to play it but the fan, is being really loud when I play my games and then it will get even louder for a period of time then go back to just being really loud, this is much louder than it was before I did the YLO fix.

-is this normal?

-should I be concerned and try to back up my data?

-am I going to have to take apart my ps3 again?

-suggestions on how to fix it?