2000 Silhouette: loud grinding noise mechanic says its in the rack ...

check hubs

Failed water pump

Don't use it like that

ball joints, tie rod ends, faulty rack n pinion, control arm bushings, sway bar end links, or you just could be hitting the steering bumpstops.

have the wheel bearings checked

Almost sound like your rack and pinion cylinder has gone bad. I would start by cleaning the area real well to get rid of the oil. With the car running have someone sit inside and turn the wheels from left to right while you stand and watch to see if you can see oil leaking and from where and also to see if you can tell where the grinding is coming from. Please do not try to clean the engine with it running as you will get burned from heat and your clothes may become tangled in moving parts.

The power steering pump is bad! God-Bless! or the rack and pinion leaks, check the pump first. the pump whines if low on fluid or bad.

seems like the pressure line to the rack&pinion is plugged.open the line at the rack see if fluid flows if not replace line if fluid flows then replace the rack.

Sounds like your fan belt. very cheap fix

If your getting a grinding noise when turning it's probably in the power steering. If you leaking fluid you have a hole, more then likely in the high pressure line or the rack and pinion is bad.

Starter has teeth that mesh with teeth on the flex plate . most of these type grinding noises are do to missing teeth on the starter gear or flex plate missing teeth .Does your vehicle have a automatic transmission ? Have you had starter replaced lately ?