reverof

My 97 LS400 seems to have a squeak normally when it first starts up, almost always when its idling if I rev the engine it will also do this.
Its not a power steering whine, more like a belt squeak.

Any ideas or suggestions before I start really getting into finding this would be very much helpful.

steve2006

Common problems are the belt idler making this noise due to worn bearings,it could also be the belt.
Easiest way to find out is to remove the belt and spin the idler pulley by hand listen for rough bearing noises and check for play in the bearing.
Other items driven by the belt are the PS pump,alternator and AC compressor.
Mine makes the same noise in cold weather for a few minutes and has been like this for a few years with no further deterioration.
The belt is auto tensioned and is removed by using a 14mm (I think) on the tensioner center bolt to release the tension then removing the belt.
There should be a diagram on a label under the front edge of the hood showing the routing for refitting

etex

May be near time for the fan bearing bracket to be replaced. Check this while the drive belt is off, also.

reverof

Well at least I know I was going to be looking in the right places. I know its not the PS pump as it was replaced right before I got the car, but the others.... we shall see!

Thanks guys for your input.

JimsGX

First thing before checking the other stuff above, I'd turn off the A/C and rev it up to eliminate the clutch slipping...