Grating Noise in Front End When Bump or Bottoming Out

X 2 on Islandman's suggestion about rubbing on sharp turns. Had the same problem with my Dodge van exiting my drive with a turn and just a slight bump at the end of my drive. It doesn't take too much of a turn to hit the limit stops on the Dodge with their wide turning radius!

If a few shops have looked at it, it is very unlikely to be any of the obvious things mentioned, like tire rub, etc. I assume it happens with the wheels straight, as it is pretty hard to get a full compression when sharply turned (and very hard on parts). Noises under suspension compression can be tough to find because the spring keeps you from actually being able to duplicate it on the hoist. Sometimes the only way to find it is to disassemble the parts to look for damage, or remove the spring so you can move the suspension with it on the rack.

Most likely it will turn out to be something like the a-arm pivots getting metal to metal at some point, a shock with a bad spot, loose wheel bearings allowing the rotor to hit the shield or something else.

Good luck finding it, and when you do, make sure you do the other side at the same time, as it will probably be going also.

Sounds to me like the tire is contacting the inner fender when you hit a bump. It's easy to verify, get a flashlight and look at the inner fender above the tire. If it looks sanded in a spot, that's it. The spot probably isn't as wide as the tire.
Check the tire sidewall inside and out to see if you can see evidence of rubbing. Sometimes the tire sidewall will hit a projection on the fender lip and it sounds horrible because it vibrates the fender. Those are easy fixes and nothing to be worried about. No vehicle is perfectly symmetrical so it can happen on any vehicle especially as they get older and the springs sag.

It is in the suspension. You need to have the ball joints and A-arm bushings looked at and replaced.

Sounds like a metal to metal scraping noise that only happens if turning the wheel tight in one direction; my PW Excel did it when turning hard right like out of a driveway. Had the lube guys smear some grease on the contact area and the noise went away. Nothing to worry about, just put some grease on it; go to an alignment shop if you are worried.