very loud zzzzering noise help diagnose

ok so throughout the winter a very loud zzzzzzering noise has gotten progressively louder and is audible upon giving it gas especially between 1.5 - 3k rpms. it actually drowns out any other engine noise. (definately not a whistle, but more "electrical" sounding)
im pretty sure its from the power steering pump, but after reading through a bunch of other threads im not sure because they described more of a whine.

heres my main questions: would a bad PS pump cause that sound or a bearing? (i know bearings usually whine) the PS fluid level is good and no foam. my steering seems to feel fine.

96 4.0L stock engine parts

Other things to look at: fan blades hitting something or harmonic balancer hitting timing chain cover. The harmonic balacers sometimes start to come apart and worn motor mounts can let the fan hit the radiator. Neither condition is good. I would not guess power steering pump.

Could also be the timing chain itself or the idler pulley.

thanks guys ill look into it. otherwise im still free to more suggestions

I've seen similar sounds come from a loose or cracked flexplate.

All of the above, and you might also check the fan clutch.

Buy yourself about 3 feet of clear vinyl tubing (most hardware stores, some auto parts stores) and use that as a listening tube, one end held in your ear and then move the other end around the engine compartment VERY CAREFULLY while the engine is running. You should be able to isolate the general area and that should make your diagnosis easier.

Again, moving belts, pulleys, fan, etc., BE CAREFUL.

thanks again guys. today i went and borrowed a mechanics stethoscope down the street and concluded it is the PS pump. the mechanic agreed. everything seems fine (in terms of the pump doing its job) so im just gonna ignore it for now. ill try to post up an audio/video so you can hear for yourself

cphillips said:

thanks again guys. today i went and borrowed a mechanics stethoscope down the street and concluded it is the PS pump. the mechanic agreed. everything seems fine (in terms of the pump doing its job) so im just gonna ignore it for now. ill try to post up an audio/video so you can hear for yourself

Click to expand...

Mech stethoscope is a great tool, I currently own three. The downside to the Mech stethoscope is the metal end, which can and does pickup vibrations from other equipment in the engine bay. Sometimes you can't tell for sure which parts are the original source of the noise due to harmonics. That is where the tubing comes in handy to identify the general area, then use the Mech stethoscope to isolate the source.