Recent noise - when starting up from a full stop, there is a brief rattle from under the car. Sounds like something loose rattling in a bracket. No other issues: transmission shifts well, braking is fine, steering is fine. No noise during upshifting or downshifting. Only from start. Any ideas?
Open the hood and start wiggling brackets to see if anything is loose. If you can’t find anything on top, put the front end up on Jack stands and check underneath. It might be easier to get under the SUV if you remove the wheels. Removing them will make checking the suspension easier too. This gives you a chance to inspect for anything else under the hood that needs attention.
More than likely, a heat shield on the exhaust system has become loose or broken, and the good news is that–although the noise is annoying–a rattling heat shield is not dangerous. In a case like this, the easiest fix is to secure the rattling/vibrating part with a large screw-type clamp, and most mechanics should be willing to do this for you. By contrast, a dealership would likely refuse to do that.
Have the car put up on a lift in order to determine exactly what is rattling/vibrating.
If you are lucky, it will simply be a loose or broken heat shield.
I second VDCdriver on the heat shield rattle.