It shouldn't make noise. If it does, replace it!
Hard to say. However, if the "rubber gasket" you're talking about is the center bushing on your harmonic balancer, that could throw your Harmonic balancer out of balance. This could easily make it shake to beat the band which in turn could be the knocking noise you're hearing. I suggest you get it looked at immediatly. If that is what happened, your engine won't survive long.
== == I do believe if you hear a knocking noise that your crank shaft could be failing. Which means you will need a new engine. Have it checked out. Replace the harmonic balancer they will make a bad knocking noise. When you start it and the oil light goes out and it knocks, this is what is wrong with it.
it'll sound like a hollow tapping sound while rotating.
not always usally makes an noise close to a rattle or knocking hence harmonic.use a broom stick or hose to use as a listening device to locate the exact place of your noise could be starter sticking in(ect...)
It could be the harmonic balancer. This is the first pulley on the engine drive shaft that drives all the other pulleys with the serpentine belt. It is quite easy to look at it and see if the rubber has deteriorated. I had this problem with my '92 PA.
To remove the harmonic balancer from a Nissan Maxima, first you need to removed the center bolt. After that, you can use a puller to remove the harmonic balancer. Before you do this, make sure you disconnect the battery and remove the drive belts.
The balancer is made of 2 pieces That have a rubber piece in the center of them that hold the balancer together. If the balancer comes apart YES it will knock / make noise and the engine would vibrate/shake. You would be able to move 1 piece of the balancer with your hand if that was the case. Check it.
loosen the center bolt and get your self a harmonic balancer puller just make sure you loosen the center bolt enough but not too much but you need a balancer puller.
It could be your harmonic balancer.
did you disassemble the engine to determine the rod condition? some harmonic balancers will make a knocking sound when they go bad