Noise when ICE kicks in

2010 Prius began making popping or clunking noise at around 130,000 miles. Sometimes it sounded like a metal against metal, but sometimes it didn't. It did this when letting off accelerator and then again when pressing on accelerator. It also did it at highway speeds after going down hill and the gas engine kicked back on. Took it to the Toyota dealer. They didn't know what it was. Left it there for them to check it. They finally said it could be the engine/trans-axle damper or the transmission. Picked it up and headed back home. It began making a constant, repetitive banging of clanging noise. Turned around and went back to the dealer. After several days the dealer said it was the engine/trans-axle damper. They wanted $2,350 to repair and wouldn't give an answer to the question "what if that doesn't fix it."

Called another Toyota dealer and they said they had never heard of the engine/trans-axle damper. Had the part changed at an independent mechanic in order to save $875.

The car makes the same popping or clunking noise, But not the constant, repetitive banging or clanging noise.

I have watched the display on the dash and on the highway it always makes the noise after going down hill when the gas engine kicks back in. It will sometimes do it by letting off on the accelerator and then pressing the accelerator. It doesn't make the sound at slower speeds.

My wife is not afraid to drive it out of town. Any help would be appreciated.