Humming From Engine Bay - Corolland: the Toyota Corolla Forums

So I started hearing this medium pitched humming sound coming from the engine bay. The sound gets slightly louder at higher RPMs. The sound is present when the care is in gear, when in neutral, and when parked. I think they key to solving this is the fact that when the I'm parked and I turn the wheel a few degrees in either direction the sound completely disappears. It also goes away if I turn the wheel while driving also, circling around a round-a-bout for instance. As soon as I turn the wheel far enough to feel tension in the steering column the sound is gone. So ball bearing? CV? Help? Thanks.

Have you checked your power steering fluid level? Was your power steering fluid ever replaced?

The power steerling level is good but it has never been changed. Could this be the problem?

I don't know. I'd have to hear it.

okay I'll post a video later

Okay so the sound doesn't come through well in a video but I do have a new piece of information. I decided to try and tighten the power steering pump pulley. I gave it a few cranks and noticed the sound going away. I tightened it some more and eureka the sound disappeared. The issue is it came back after driving a few miles. Now I only tightened it to the point where eventually the serpentine belt started turning with it. I stopped torquing it after that. Tomorrow I'm gonna hold the serpentine belt with something and tighten the snip out of it and probably flush the power steering fluid also. I hope this resolves the problem but is it possible the pulley is bad? Like it doesn't feel loose at all but the tightening worked temporarily. Could it be the power steering pump itself and tightening the pulley just temporarily moved the pump in a way to stop the noise? I did notice the power steering pump is COVERED in oil (probably why I have to add a quart every thousand miles). Not sure if the pump can be damaged from being covered in oil. Hope this helps you help me diagnose this snip.

Oh and I forgot to say before this is a 99 CE

If your power steering pump is humming, leaking profusely, with free-play in the bearing, and wear on the pulley mount flange and threads, why not replace your power steering pump?

http://www.rockauto.com/catalog/x,carcode,1432911,parttype,7380

Yeah I think I'm gonna replace the pulley and see if that works and if not i'll replace the whole pump. I'll update with how it goes.

The bearing is in the pump. You need to replace the pump, and inspect the pulley.

http://www.rockauto.com/catalog/x,carcode,1432911,parttype,7381

I replaced the pulley and this has fixed the problem. The nut holding on the old pulley literally came off without a ratchet or anything. I just used my hands. The ridges inside the pulley were also fairly worn. Thanks for all the help!

Wow. So it's your engine that take a quart of oil every 1000 miles.