Wheel bearing?
it is time to change bearing on that pulley
Noise from floor on 96 Nissan Maxima could be as a result of poor shifting. This often occurs when you use the wrong gear oil.
loose exhaust
You need to be more specific. There are many kinds of engine noise! From your description it can be anything from a blown rod to a belt!
he he he
I am hearig a similar whirring noise in my 04 Maxima that increases in pitch as the car accelerates. I suspect it is the idler puley. I'm planning to replace it in a couple of weeks and will report ba.
Coming from the drive wheels? Could be worn CV joints
Stop driving it because if the chain goes you will ruin the engine. Get it fixed.
usually it is a loose belt
water/friction
if your horn is stuck on makin noise pull the fuse out... or you can remove the whole horn assembly from underneath the hood
Could be the CV joint is dry or has failed.