I have a 99 lincoln continentil how can i tell if my heads are blown or the gasket

SOURCE: head gasket blown

there are many was a head gasket can blow . sometimes they just leak to the outside sometimes they leak to the coolant and then it blows out your antifreeze. if you have a blown head gasket you will see it when you pull the head. and yes you should hace the head checked at a machine shop and install with a new head set never reuse a gasket .
later paul

SOURCE: over heating

try having your radiator pressure checked , or replacing your cap

SOURCE: head gasket sealant

As a A S E Certified Tech I Do NOT RECOMEND ANY "QUICK FIX" ADDITIVES Especialy for such a Critical Engine Component

More Costly but Also More effective is to Tear down Engine and Replace Head Gasket as You may have A Cracked Head Or Block That NO ADDITIVE will TRUELY REPAIR PROPERLY

Rough Estemate In USA Midwest $350.00-$600.00 For The Real FIX yep they vary that wide Some of us Love Helping PEOPLE the Rest LOVE THE MONEY MORE

SOURCE: how to replace blown head gasket

u have to start by removeing ur headers dont forget to take ur blown gasket to ur local part store to make shure u get the rigth one

SOURCE: blown head gasket

I would change both, as well as use new head bolts. Make sure your heads are not warped or cracked, especially the one that is leaking. There may not be any need to change the head if it is not cracked. These are prone to blowing a gasket especially after 150K miles or so. It will not cost a huge additional amount to change both head gaskets since the engine will have to be disassembled down to the heads anyway. Hope this helps you, Rick