I've got a knocking or clunking sound on my lifted 2004 xterra that seems to be coming from just ahead of the dashboard at the firewall, in the center. I hear it when driving on rocky roads, when the road gets bad. In fact it started when I drove a lot of dirt roads on a recent trip through Honduras, Nicaragua and Costa Rica. It's a pretty loud knocking sound, but it doesn't really sound like metal on metal. At first I thought it would be a loose shock absorber, as it maybe sounds like it happens when the front tires go down, rather than up. We checked the front suspension and steering parts: Rebuilt the ball joints. Rebuilt the center link. Welded body panels in wheel wells and below the windshield, where the wipers are. Checked the Bilstien shocks. Then I thought that it may be something in the roof, because I can feel the knock when putting my hand at the top of the windshield, so we took the headliner out, and removed the fairing, basket, and the light rack. Still getting the knock. Any ideas? Motor mount? Windshield mounting?

Cars & Trucks - Nissan - Xterra - 2004 Nissan XTerra