2002 Xterra supercharger rattle, normal ???

[mtrhd101]

I own an 02 Xterra SC 78K, the supercharger makes a rattle at Idle.. Is this to worry or is this normal ? The noisy seems to go away as the revs come up just a little.. thanks

[Eikon]

I have no personal experience with superchargers...

but I dug this up with a google search.. http://www.gadgetonline.com/Super.htm

The supercharger does make noise, it is supposed to. Under boost it will make a wonderful whine sound that most find very pleasant. At idle it will make a rattling like sound. That is from gear slack in the nose drive. The supercharger uses straight cut gears in the nose drive and at idle there is no load on the gears that they tend to rattle back and forth a bit and that presents as a rattling sound. It should go away if the engine is rev-ed up just above idle. This is all very normal. As the supercharger ages the rattle sound at idle may get louder. I replaced my nose drive at 65,000 miles and the rattling sound was greatly reduced.

[Dano]

Can you get out of the car and identify the vicinity the rattle is coming from? i.e. top of motor, bottom of motor, front, back, transmission area, etc

-Dan

[mtrhd101]

It's the SC, I took the belt off and the rattle stopped..

[obby]

Is the noise coming from the nose or the rotor housing? Either way it's almost rebuild time, however if it's in the nose and you're low on cash you might sneak away with just replacing the coupler(get the new fangled green ones with tougher materials). Alot of people just ride the rattle out though, just depends on how neurotic you are

[mtrhd101]

I took it apart, the noise was partially coupler but the noise concerning me was coming from rotor contact.. The rear bearings had just enough play to let the rotors touch slightly, that was the chirping sound.. Yes, time for a rebuild.. 70K, is this normal ??