Please help me identify what the rattle noise could mean. Ita. 2002 Nissan Xterra with 113k miles. Video here: https://youtu.be/dncO3Onx1ts
I’ve heard bad water pump bearings make a sound like that.
I can’t specifically identify it on the video, but I suggest you start with an overall evaluation of the engine’s condition, as well as trying to locate its origin with a mechanic’s stethoscope. An engine condition evaluation will include a compression test and an evaluation of the condition of the spark plugs.
My wild guess, and it is no more than that, is that IF your engine has a timing chain… look there. It sounds exactly like my ol’ '89 pickup did when it needed a new timing chain kit at 200,000 miles.
My second wild guess would be that there’s something tired or worn out in the valvetrain. That can be evaluated by a competent shop by doing things like valvelash measurement and testing the springs.
Yup, it needs a hands-on look-see by a competent diagnostician. Let us know what he finds. We do care.