On a 2002 Mercury Grand Marquis :
No , the 4.6 liter Single Over Head Cam , V8 engine has ( 1 timing CHAIN
to each cylinder head , so there are 2 timing CHAINS )
Chain
The 2005 Mercury Grand Marquis , 4.6 liter SOHC , V8 engine has ( 2 ) timing chains ( 1 timing chain to each cylinder head )
You use a timing light to check the marks on the timing chain/belt.
The 4.6 liter SOHC , V8 engine in a 2000 Mercury Grand Marquis has ( 1 ) timing CHAIN to each cylinder head ( so there are two timing CHAINS )
The grand am does not have a timing belt it has a timing chain.
The 3.1 liter V6 engine in a 2002 Pontiac Grand Prix has a timing CHAIN
diagram for 2003 grand marquis belt installation
On a 1996 Mercury Grand Marquis : The 4.6 litre SOHC , V8 engine has ( 1 timing CHAIN to each cylinder head , so it has 2 timing CHAINS )
The 2.2 litre four cylinder engine in a 2002 Pontiac Grand Am has a timing CHAIN
Chain
Take the top timing cover off and look at it.
NO belt in the 302cid engine of a 1988 Mercury Grand Marquis. it is a chain with gears