Any suggestions?

You have to make a structural repair and the right way is to use an injector repair kit by inserting plugs and filling the cavity with 2-part epoxy or use carbon fiber staplers its called the stitching method,

Injector repair method

Stitching method using carbon fiber staples

That said, 1st you need to determine if this is a structural or non-structural crack. Structural cracks are usually vertical cracks that are wider at the top or bottom or cracks that are 1/8" or wider, etc.

If it's structural it should be fixed right away or with time it will get worst.

Running a bead of calking over it will do absolutely nothing.

Good luck

Thank you