LR3 AJV8 Faint Knock

[hydronaut]

Doesn’t sound like a rod knock and seems to be most prevalent on top near the fuel rail. Increase a bit during acceleration. Any ideas what this might be. Not even sure when. It started or how long it’s been there but paranoid about any noise. Any opinions appreciated.

https://youtube.com/shorts/CVvFgUG3nTE?si=kgIKMGq860UHhFfi

 

[hydronaut]

Second link is with increased RPM.

 

[K-rover]

Pulley going bad. Or even fan clutch could make a noise like that. I'd pull the belts and spin all the pulleys by hand. See if you have any abnormal noise or movement.

 

[hydronaut]

Doesn’t sound like a rod knock and seems to be most prevalent on top near the fuel rail. Increase a bit during acceleration. Any ideas what this might be. Not even sure when. It started or how long it’s been there but paranoid about any noise. Any opinions appreciated.

https://youtube.com/shorts/CVvFgUG3nTE?si=kgIKMGq860UHhFfi

Pulley going bad. Or even fan clutch could make a noise like that. I'd pull the belts and spin all the pulleys by hand. See if you have any abnormal noise or movement.

Thanks. Was planning on putting on new belts. No harm in pulling off each pulley and checking each one. Also have an alternator I plan on rebuilding I can swap out too.

 

[K-rover]

Thanks. Was planning on putting on new belts. No harm in pulling off each pulley and checking each one. Also have an alternator I plan on rebuilding I can swap out too.

I recently had a bad noise coming from the engine bay. I couldn't tell where it was coming from. I pulled the belts and spun each pulley. The Ac pulley sounded like it had rocks in it. Replaced the compressor and Allis quiet again. You should be able to spin them by hand while still in place.

 

[hydronaut]

Update:

It was the tensionor pulley. While I was there replaced the bearings in all 3. Nice and quiet now. Only cost me my time as I had a bunch of bearings lying around.