Catalytic converter failing?

[TheDon]

YouTube - ‪Aveo engine noise‬‏

link to the video

[petrified.rabbit]

do that again and take the oil cap off.. do you hear it more distinctively?

sounds like cam/lifter noise, it definitely sounds like top end.

[TheDon]

showed the video to my mechanic. He said it sounds a lot like rod knock

[daug1502]

Wow, I can't tell from the video. I had a buick century with a bent rod in it. The thing ran fine for the 6 months that I had it, even drove it to the junkyard. But it did make a noise not unlike that. Had a couple cars with bad lifters that made a noise like that but much quieter. Could a lifter be completely out?

[TheDon]

I'll run the engine tomorrow with the oil cap off and then possibly with the valve cover off and listen for noise.

[thehunterooo]

I don't think it is a rod knocking, should check the valves if you can.

[ontarian_frog]

Yeah, first thing I would do is pull the valve cover off and see if anything is broken/damaged. I'm guessing a broken lifter/rocker arm.