2005 4Runner engine rattle

Look for a heat shield loose, possibly on the exhaust manufold or on catalytic converter. With engine running take a stick of some type that is heat resistant and push on any metal or plastic panels or shields in the engine compartment. HTH, davidj92

We had a guy here recently -- the past two or three weeks -- that had a similar complaint. It turns out he was selecting a gear that had the motor doing about 1500RPM or slower, and the "problem" went away when the engine speed increased.