I have started noticing a rotational metal sound coming from my accessory side of the engine that is best described as "metal rubbing sound". I replaced my idle and tensioner pullies within the last year and everything on the accessory side seems to spin freely. It occurs at idle and changes pitch or comes and goes with rpm speed. I haven't noticed any other symptoms other than this alarming noise. It is most noticeable at low rpm. Attached is a video from around the crank pulley which it seems to be most noticeable at. Unfortunately, I pick up the noise some as I move across to the other side of the oil pan. I'm afraid this might be something related to the crank and bearings. Anyone encounter this same noise before and know the most likely culprit?
https://drive.google.com/file/d/182G...ew?usp=sharing

Is it a bad idea to remove the accessory belt long enough to run the engine and see if I still hear the noise...for sure ruling out the other accessories?

 

Oh, could still be just some accessory rotational thing? But, why not just do an oil change & check the oil for metal? Also, go one step further and send an oil sample into Blackstone Labs for a professional diagnosis?

 

Someone recently posted about their idler pulley making vibration/noise. maybe you should check that

 

I checked all of those and they seem to spin freely with no play.

 

Oil looks good. My magnet plug is clear of any metal. Oil was last changed on 7/29/22. Dang, this is a PIA to figure out.

Nothing seems to change with the sound during clutch engagement or transmission engagement. Friend thought it could be a pilot bearing but we don't use one.

Not sure if there are other bearings related to the crank located more on the outside of things which wouldn't show up as metal in the oil. Hmmmph

 

I would still send a sample to Blackstone so they can check all the other non metallic (bronze & alum, etc) wear metals

Will give you some peace of mind so you can move fwd?

 

With the engine cold, take off the accessory belt completely. This disables your water pump also. Start the car and listen to it, maybe 2 minutes at most and shut it off. If you still hear the noise it is timing belt or engine internals related. I get a squeal from my timing belt during cold starts. Seems that the belt can rub on the crank sensor wheel. Stops when engine is warm.

 

Thanks for the reply, I should have provided an update 2 days ago. That is exactly what I ended up doing and the noise goes away with no accessory belt. Best I can tell, this appears to be my water pump. The noise really resonates down low to the crank area so that is why it is so hard to be 100% sure but I think I could feel it vibrating on the water pump pully slightly when it makes the groaning noise.

Have a new gates pump on order and have some work to do. I will update my post with final confirmation for others who may run into the same noise.

 

Just following up. Got the water pump replaced and all is good. The sound was the bearing inside the pump going south.