JEEP CYLINDER HEAD GASKET BLOWN

What Could Be The Most Likely Causes, And If It Is A Blown Head Gasket, How Expensive Could That Be? Thanks, Abbie

If You Don't Have A Blown Head Gasket And You Put Bars Leaks In The Radiator And Run It Through The Engine Will It Mess Your Engine Up?

Recently I Noticed A Foamy Yellowish Color As I Was Filling My Oil It Has Been Very Cold 30s I Never Noticed This Over Past Summer Just Had...