What are the signs of rod bearings needing to be replaced?

Hi thanks for asking; To answer your question, we can't describe noises in type/print. There is a lot of moving parts in an engine, as you probably understand, and to be able to diagnose this sound we really need to hear it for ourselves. It would be better if you could fined the locator on this website for a repair facility in your area, and let them listen to it for a more correct answer. Thanks for asking.

Check your oil pressure. I had a 97' Bonneville with a 3.8, which the oil pressure was not holding where it should of been and sure enough it was the rod bearings. It didn't make any noise though.