I have the same problem on my 95 Sable LTS
how much would it cost on a 2004 mercury sable
Heater core.
There is no fixing a broken motor mount. Replace them with a new ones.
You will have to take it apart to determine why it's not working then you can fix it.
Fix the drive belt.
Maybe the belt tension is too tight. This very same thing happen to me on a 92 Jeep Cherokee. Is the belt the right belt ? Length , width and design Check your routing If you did not move any components ( fly wheel ???? ) then look at the belt. looks like you got to change the belt again anyway get a belt from a dealership
Physical damage to a cylinder is seldom repaired. More often the motor is replaced.
I have a 1996 Mercury Sable and it did the same thing. The fix was a new transmission. My mechanic noticed that the car was running higher RPMs than it should have after replacing an engine that blew a rod through the engine because of the bad transmission.
Your local auto parts store can help you with that.
The oil pump inside the engine is probably busted. If you start and run it you will probably ruin the engine. Probably $100 to fix now or $7000 to fix if you ruin the engine. Don't drive it or run it any more.
These parts are only fixed by replacement.