Engine Rattling only when in Drive and moving while accelerating

[George_San_Jose1]

Barky’s is a good idea, esp if it sounds like shaking a can of bolts. Besides the fuel octane level, overly advanced ignition timing or too wide of spark plug gap can cause that. It could also be just an exhaust shieldis rattling. Driving in gear and giving the engine gas puts forces on the engine mounts that don’t occur when not in gear. That can twist the engine and transmission enough to cause an exhaust shield to rattle. Ask your shop to inspect the engine and transmission mounts and exhaust system shields.