This is very most likely to be a failed temperature blend door actuator motor.
The motor is attempting to move the blend door, but due to broken gears inside, it can only get so far and then the door drops back down - thump thump thump.
See "Related Questions" below for more on this relatively easy & not-too-expensive repair.
If "heater coil" is just another term for "Heater core", then yes, most all cars have them.See "Related Questions" below for tons of information about Taurus / Sable heater cores.
No 2011 Mercury Sable model , but there is a 2011 Ford Taurus
99% sure the Taurus radiator will be a perfect match to the Sable's.
No one knows if:The heater is NOT blowing - or blowing on high speed only, or... The heater IS blowing, but the air is NOT hotEither way, the "Related Questions" below will get you started
No, a Generation 2 (1992-1995) Taurus/Sable Windshield will NOT fit a Generation 3 (1996-1999) Ford Taurus/Sable.
No they do not
The Mercury Sable and the Ford Taurus will have DOC in printed on the engine if they are dual overhead cam engines. The symbol should be on the top of the engine.
the air conditioner and heater are two separate things.(not connected) ;) it may have a fuse. or the it could just be bad.
Yes, it is identical.
Yes, it does.
Yes.
Just one handles the job. See "Related Questions" below for more about Taurus/Sable fuel pumps