Is it possible to have a torn acl without having pain any more?

Yes!: Acl tears typically cause initial swelling, but usually resolves on its own. After an acl is torn, some people get back to their normal state and normal daily lives. However, if you plant your foot and push off to the side (such as in cutting sports), the knee can shift and cause damage and/or swelling. If this occurs repeatedly, and acl reconstruction is recommended.

Acl: Yes it is common not to have pain after the acl is torn. The pain usually occurs when your knee buckles because of the instability.