According to the 2003 Mercury Grand Marquis Owner Guide :
It came from the factory with a 50 / 50 mix of distilled water and Motorcraft
Premium Gold Engine Coolant
( that's YELLOW color , meeting Ford specification WSS-M97B51-A1 )
how to changing engine coolant on a 1993 mercury grand marquis gs.
The thread on cap on the engine coolant reservoir is the " radiator cap " on a 1995 Mercury Grand Marquis
On a 1997 Mercury Grand Marquis : The thread on cap on the engine coolant reservoir is the 16 PSI pressure cap / radiator cap
Location of coolant temperature sensor on a 2003 Mercury Grand Marquis?Read more: Location_of_coolant_temperature_sensor_on_a_2003_Mercury_Grand_Marquis
You probably have a bad head gasket on your engine.
I was looking at a picture in the 2003 Mercury Grand Marquis Owner Guide and it shows the power steering fluid reservoir at the front of the engine compartment between the engine coolant reservoir and the engine air filter box
On a 1997 Mercury Grand Marquis : The thread on cap on the engine coolant reservoir is your 16 PSI pressure cap / radiator cap
The engine in a 1993 grand marquis is a 4.6 litre/281 cubic inch.
The thread on cap on the engine coolant reservoir is the pressure cap / radiator cap for the engine cooling system
NO belt in the 302cid engine of a 1988 Mercury Grand Marquis. it is a chain with gears
According to the 2004 Mercury Grand Marquis Owner Guide : The engine cooling system capacity is ( 18 liters / 19 U.S. quarts ) It came from the factory with a 50 / 50 mix of antifreeze and distilled water
At the front of the engine , towards the drivers side of the engine ( power steering fluid reservoir on a 1998 Mercury Grand Marquis )