ballpark $1500 sight unseen
There is only one fix. Remove and replace the gasket. This is a major repair that should only be attempted by an expert.
if it is pumping out when you rev engine then you have a blown head gasket
You must replace the defective gasket. There is no other permanent fix.
blown head gasket
There's more than one cause of oil in engine coolant but the most common is a blown (failed) head gasket.
Oil in the radiator or water in the oil which will show up as white gloopy stuff on the oil level stick.
The approximate cost to change an oil pan gasket, on your Ford Taurus, is $125. The oil pan gasket can be purchased for $10.
I just had the timing cover gasket on my 2000 Ford Taurus replaced...Cost of Repair was $513
on 1991 ford taurus 3.8 how do you replace a timing cover
How do you replace freeze plug 1999 Ford Taurus?
If this is a nice car then spend the money and have the blown head gasket repaired before you try to sell it. With a blown head gasket it is only worth what someone will pay. Would you buy a car with a blown head gasket? I sure would not, as there is no way of knowing how much damage has been done. I would not touch this car as it stands now and neither will most people. It is worth very little with the gasket blown.
A miss on one cylinder is caused by defective spark plug, plug wire, burnt valve, or blown head gasket. Replace all plugs and plug wires. If the miss is still there run a compression test.