My dad has a 2000 4runner with 230,000 miles on it. For the past year or so there has been this rattling noise while driving that seems to be coming from the driver side part of the truck like around the backside of the engine or possibly underneath. The noise sounds like a washer rattling around on a bolt or something that's not tightened down or a loose chain.
Anyways, I've been under the truck multiple time, looked around in the engine bay near the firewall and have found nothing. Today I go back out and looked again and noticed the stabilizer link bushings are bad again but I also noticed the boot for the inner tie rod is off and looks like their is some black grease on it. I push the boot back on the steering rack but as I was doing that I noticed that the steering rack is leaking oil around the big bolt on the side facing the rear.
This got me thinking that maybe the rattling noise is coming from the steering rack. Could a bad / leaking rack be making this noise or something else like the stabilizer link bushings? In the past two years, I've replaced the inner and outer tie rods and such but don't think that's the problem. It only makes that rattling noise while driving down the road and it's pretty annoying.