What causes the engine to rock when I shift the automatic transmission into drive or reverse?

If you notice that the engine twists from side to side when shifting between forward and reverse, there may be a broken or loose engine mount.

This means the engine is not fastened properly to the car and any gear change will cause a rocking sensation.

If the condition worsens, you will notice vibration and noise while the car is on the move or idling.

Automobile Association of Singapore