Then disable/disconnect the top FAN.
Check the system temps.
If little or no change...leave the top disconnected and try the same with the side fan.
You might also consider quieter fans ot larger fans that rotate at lower RPMs.
Let us know.
I am currently using an NZXT M59 case and in it one intake side fan and one rear exaust fan.
I once had it fully loaded with 4 fans (Top exaust, front intake, side intake and rear exast) but it got a little noisey for me...
ANyways, I am currently using a Hyper 212+ as my cpu cooler of choice, and was just curious is a top, rear exaust fan would be of any benefit. I once had one in before I upgraded to the Hyper 212+ but thought that it would mess up the airflow from the coolers fan to the exaust fan since its pulling up while those two are pushing back
Any ideas would be appreciated. Thx