The 4 cylinder has a timing belt
timing CHAIN
The 3.8 liter V6 engine in a 1991 Mercury Cougar has a timing CHAIN
It must have a timing chain because Gates ( they make timing belts etc. ) only lists a timing belt for the 4 cylinder engine on a 2000 Mercury Cougar
On a 1996 Mercury Cougar : The 3.8 liter V6 engine has ( 1 timing CHAIN ) The 4.6 liter V8 engine has ( 1 timing CHAIN to each cylinder head , so there are 2 timing CHAINS )
The 2.5 litre V6 engine in a 1999 Mercury Cougar has ( 1 timing CHAIN to each cylinder head , so there are 2 timing CHAINS )
It has a cam chain that normally requires no maintenance.
Chain and it is a very (~1000.00) costly fix.
Dual chains
Timing Chains (2) with respective guides, tensioners and sprockets.
The V6 uses chains. The I4 uses belts.
The 2.0 litre four cylinder engine in a 2000 Mercury Cougar has a timing BELT
To replace the timing chain on a 2001 Mercury Cougar with a 2.5L engine, first, disconnect the battery and remove the engine covers and accessories obstructing access to the timing chain. Next, align the timing marks on the crankshaft and camshaft to TDC (top dead center) before removing the old timing chain. Replace the timing chain and tensioner, ensuring proper alignment with the timing marks. Finally, reassemble all components, reconnect the battery, and run the engine to check for proper operation.