if there is a crack in the timing chain casing is that easily fixed?

The timing chain has enough play/slop in it that it has worn a hole in the cover. This runs on the camshaft /crankshaft. This needs to be fixed by an experienced mechanic.

The timing chain casing can be fixed by any shop that's capable of doing aluminum welding, but if the casing is broken in two pieces you're better off getting a new or junkyard replacement. Welding will warp the part and make getting a perfect seal very difficult, if not impossible.

Let me add that your chain and tensioner need replaced due to play.