Front End Groaning/Knocking Noise

My 98 2.3CL automatic has been making some very loud groaning/knocking noises under a very specific set of conditions:

• Decelerating from ~60 to 50 mph (foot is off of the gas and brake), but only if the steering wheel is straight or to the right
• Making a hard right turn with foot off the gas (like a horseshoe exit from the expressway
• Giving a good amount of gas in Reverse (both when the car is moving in Reverse, or when I rev the engine in Reverse with the brakes applied and the car is not moving)

It's an awful sounding noise, like metal is groaning and ripping apart or grinding against something moving. I'm wondering if it's a bad engine mount? Any thoughts?