One problem related to engine noise has been reported for the 1997 Toyota RAV4. The most recently reported issues are listed below.
My rav 4 - 57348 miles. It started making a tapping sound in the engine and it has makes a metal on metal vibration upon acceleration and especially when I make a gradual left turn and decelerate. I brought it into the dealer. They say it may be that the lifters are a bit worn and that this will not harm anything. This is odd because a new engine was placed in the car at 49,000 + miles. They could not identify what the vibration noise was and said that it is possibly a rock in the brake system. I know what that sounds like and strongly disagree with their analysis. The noise is definitely coming from the engine.