New crankshaft bearings making noise

Good morning,

What was the clearance of the bearings when you installed them?

https://www.2carpros.com/articles/engine-noises

Can you upload a video of the noise so I can hear the noise?

Roy

I do not have a sign in for your drop box and cannot hear either file.

Roy

Listened to both files and it really sounds more like connecting rod rattle than main bearings. When you replaced the bearings the first time did you check the sizes of the original parts? Was there any damage to them? What was the reason for the rebuild?

Some manufacturers like to use every part they can so they will take a crankshaft that might be just a bit out of specification and grind it to the first undersize or even use different bearing sizes to make the clearances correct. Then you buy the standard parts from the parts store and discover that they are a loose fit. The only ways to check for those issues is to look at the original parts and the service manual to see exactly what their procedures are. For instance one make had bearings in multiple "off" sizes designated by color bands, you would measure the journal and then mix the bearings to get the correct clearance. The various bearings were only.001 thousands different so you might use a.002 and a.003 to make up for the true size of the journal.

You are welcome, sorry it isn't better news.

You are going to be doing a rebuild for this. This means breaking down the motor and replacing the mains, rod bearings, pistons, rings and a full gasket set.

I attached a site for you to go to. They have the engine manual and well worth the money.

https://www.tradebit.com/filedetail.php/281479066-2009-2015-chevrolet-spark-service-and-repair-manual?a=506906

Roy

Did you replace the mains and rod bearing? If you did, what was the clearances you set the bearings at?

Did you verify the oil pressure?

Roy

As Roy alluded to, once those parts start to fail there isn't anything you can really do other than open the engine up and see what the issue is. Say the bearings are bad, until you look at them and see what has happened with regards to the metals they are made out of has done. It could be that you will only need to replace the rod and main or maybe just the rod bearings, but if a bearing has started to flake apart or worse more than one, those pieces need to be flushed out and removed, then measure the parts in question and see what can be done.
The other option would be to find a used or remanufactured engine and swap that in and go through the one you have at a different time.

You are welcome.

Roy