Sudden odd noise

This morning my '96 Avalon started making an odd metallic groaning noise when I accelerate. It makes it whether I’m moving or in neutral, and it only makes it during acceleration - it doesn’t happen when I’m cruising at speed.



I checked the oil, and we’re still good there. The noise is irregular as in it doesn’t happen consistently when I accelerate. I can avoid it if I accelerate very slowly. It seems to be at a consistent pitch and volume no matter what speed I’m going.



Does anyone have any idea what this is? Or more importantly how much it will cost?

I am going to take a shot in the dark that you have a bad heat shield on the exhaust.

Agreed; likely the heat shield and these can often be repaired without parts replacement. Check with a muffler shop.

If the noise seems to be coming from under the hood, you may have a bad bearing in the alternator, idler pulley, A/C compressor, or anything else under there that’s turning with the engine. But if it seems to be coming from elsewhere, I’d agree with the heat shield diagnosis.