I have a 2000 4.8l 1500 Silverado.

The engine fan sounds too loud to me, and people look at me when I pull in anywhere. Not cool.

I've replaced the fan clutch twice, so I don't think it's the clutch.

When I look at the fan at idle speeds, there is a slight inconsistency in the blades - it seems to be uneven.

Could a marginally warped fan cause the fan clutch to engage all the time?

At WOT the fan seems to disengage for a while, if that is of any help.

If it is the fan, would an aftermarket generic fan be OK?

yes, I know, lots of questions.....

 

You should do some research on how an engine fan clutch works. The fan blades, unless missing, will not cause the fan clutch to engage prematurely. If the engine is really hot the fan will come on as designed and go off when it's supposed to. As far as people looking at you....it's probably all in your head. Only other thing I could tell you to check is to make sure the fan shroud is not broken or missing. That can cause problems.

 

Is your Air conditioning or defrost on? That will also make your fan kick on besides at operation temperature.