The same place as any other engine. Between the cylinder head (hence the name ) and the cylinder block. This is of course assuming the engine is correctly assembled.
The Ford Taurus for the most part has a V6 engine. It has 2 head gaskets. Some very early model Taurus's had 4 cylinder engines which had 1 head gasket.
There are two head gaskets,one for each head.
The 2001 Ford Taurus has ( 2 ) head gaskets for each of the V6 engines that are offered from the factory
cacked head, or (luckier) head gasket, try the gasket first.
Change the head gasket.
ballpark $1500 sight unseen
if it is pumping out when you rev engine then you have a blown head gasket
Bad head gasket or weak fuel/ spark.
There is only one fix. Remove and replace the gasket. This is a major repair that should only be attempted by an expert.
Between the head and the engine block.
I'm not a mechanic / technician but on a 2004 Ford Taurus if you have the 3.0 liter DOHC " Duratec " V6 engine you would because it has a timing chain going to each cylinder head
blown head gasket