This information can be found in your owner's manual, or under the hood on a placard. If you do not have one, then you need to get one. Dealer, E-Bay, Salvage Yard, and many online sites are sources for a manual. Use Google and search with the term, "Automobile Owner's Manual".
Spark plug order? there is no such thing.
You can find the correct firing order for your 1987 mercury cougar at www.coolcats.com, it is a website dedicated to the cougar and thunderbird.
The Spark plug location on the 2001 2.5 liter dohc is under the valve cover.
0.054 for 1999 to 2001 V6.
The plug gap for a 1995 model, 40 hp Mercury is .035 in.
According to one of Fords websites : For a 1969 Mercury Cougar ( all factory available engine sizes ) ( .035 inch spark plug gap )
first pull the spark plug boot off and check for tracks, then check the spark plug condition , it's gonna be 1 of 3 things the spark plug itself , injector , or spark plug boot. it could also be the plug wire.
.054 inch ( according to motorcraft . com )
According to one of the Ford websites : For a 1988 Mercury Cougar , 3.8 liter V6 engine : ( the spark plugs are gapped at .054 inch )
According to one of Fords websites : For the 1992 Mercury Cougar , 3.8 liter V6 engine : ( the spark plugs are gapped at .054 inch )
the gap is 5.0
According to one of Fords websites : For the 3.8 liter V6 engine in a 1988 Mercury Cougar : ( the spark plugs are gapped at .054 inch )
Same as the 1996 4.6L: .054
Screwed into the engine. Follow the spark plug wires.
A 2002 Mercury Cougar 2.5 liter plug wire diagram can be purchased from your local Mercury Cougar. It can also be found at most auto parts stores.
According to one of Ford's websites : For a 1991 Mercury Cougar , 3.8 liter V6 : ( the spark plug gap is .054 inch )
They will if it's the 3.8 L - V6 engine ( Motorcraft WR 4099 - part number ) The 4.6 L in the Mustang and Cougar take different spark plug wire sets ( Motorcraft WR 5938 for the Mustang ) ( Motorcraft WR 5935 for the Cougar ) The spark plug wire set for the Cougar has some longer wires in it )
According to the 2002 Mercury Cougar Owner Guide : For the 2.5 liter V6 engine : The spark plug gap is ( .054 inch ) *** confirm with the Vehicle Emission Control Information ( VECI ) decal , in the front of your engine compartment ***
The 1991 Mercury Marquis spark plug gap is .034. Most spark plugs will be pre-gapped by the spark plug manufacturer.
According to the Haynes guide the gap is .054 inches
Your intake manifold probably has a crack in the water jacket.
Check the Vehicle Emission Control Information ( VECI ) decal located in the front of the engine compartment ( it will show what type of spark plugs to use and the spark plug gap )