Starter just makes a whirring sound?

Hello,

If the starter is not able to connect to the flywheel/flex plate, it will spin freely and make that noise.
It is possible to have broken tooth on the flywheel/flex plate, so as the starter drive extends it is unable to turn the fly wheel.

It will be a good idea to inspect the flywheel. If there are broken tooth the flywheel will needs to be replaced.

Of course, another possibility is that the starter drive is simply not extending and spinning at the retracted position.

I have attached diagrams for your reference.

Please let me know if you have any questions.
Thank you.

https://www.2carpros.com/articles/how-to-replace-a-starter-motor