2004 Mercury Grand Marquis engine

•The air conditioning system will be disabled.
Continued operation will increase the engine temperature:
•If your vehicle is equipped with digital gauges, the gauge bars will
flash and a tone will sound every five seconds for one minute.
•The engine will completely shut down, causing steering and braking
effort to increase.
Once the engine temperature cools, the engine can be re-started. Take
your vehicle to a service facility as soon as possible to minimize engine
damage.
When fail-safe mode is activated
You have limited engine power when in the fail-safe mode, so drive the
vehicle with caution. The vehicle will not be able to maintain high-speed
operation and the engine will run rough. Remember that the engine is
capable of completely shutting down automatically to prevent engine
damage, therefore:
1. Pull off the road as soon as safely possible and turn off the engine.
2. Arrange for the vehicle to be taken to a service facility.
3. If this is not possible, wait a short period for the engine to cool.
4. Check the coolant level and replenish if low.
Never remove the coolant reservoir cap while the engine is
running or hot.
5. Re-start the engine and take your vehicle to a service facility.
Driving the vehicle without repairing the engine problem
increases the chance of engine damage. Take your vehicle to a
service facility as soon as possible.
WHAT YOU SHOULD KNOW ABOUT AUTOMOTIVE FUELS
Important safety precautions
Do not overfill the fuel tank. The pressure in an overfilled tank
may cause leakage and lead to fuel spray and fire.
The fuel system may be under pressure. If the fuel filler cap is
venting vapor or if you hear a hissing sound, wait until it stops
before completely removing the fuel filler cap. Otherwise, fuel may
spray out and injure you or others.
2004 Grand Marquis(grn)
Owners Guide (post-2002-fmt)
USA English(fus)
Maintenance and Specifications
196

splashed on the skin, promptly wash skin thoroughly with soap and
water. Consult a physician immediately if you experience an adverse
reaction.
When refueling always shut the engine off and never allow
sparks or open flames near the filler neck. Never smoke while
refueling. Fuel vapor is extremely hazardous under certain conditions.
Care should be taken to avoid inhaling excess fumes.
The flow of fuel through a fuel pump nozzle can produce static
electricity, which can cause a fire if fuel is pumped into an
ungrounded fuel container.
Use the following guidelines to avoid static build-up when filling an
ungrounded fuel container:
•Place approved fuel container on the ground.
•DO NOT fill a fuel container while it is in the vehicle (including the
cargo area).
•Keep the fuel pump nozzle in contact with the fuel container while
filling.
•DO NOT use a device that would hold the fuel pump handle in the fill
position.
Fuel Filler Cap
Your fuel tank filler cap has an indexed design with a 1/8 turn on/off
feature.
When fueling your vehicle:
1. Turn the engine off.
2. Carefully turn the filler cap counterclockwise 1/8 of a turn until it
stops.
3. Pull to remove the cap from the fuel filler pipe.
4. To install the cap, align the tabs on the cap with the notches on the
filler pipe.
5. Turn the filler cap clockwise 1/8 of a turn until it stops.
“Check Fuel Cap”illuminates when the ignition is turned to the ON
position to ensure your bulb is working. When this light turns on, check
the fuel filler cap. Continuing to operate the vehicle with the Check Fuel
2004 Grand Marquis(grn)
Owners Guide (post-2002-fmt)
USA English(fus)
Maintenance and Specifications
198

Cap light on, can activate the Service Engine Soon warning. When the
fuel filler cap is properly re-installed, the light(s) will turn off after a
period of normal driving.It may take a long period of time for the
system to detect an improperly installed fuel filler cap.
If you must replace the fuel filler cap, replace it with a fuel filler
cap that is designed for your vehicle. The customer warranty may
be void for any damage to the fuel tank or fuel system if the
correct genuine Ford or Motorcraft fuel filler cap is not used.
The fuel system may be under pressure. If the fuel filler cap is
venting vapor or if you hear a hissing sound, wait until it stops
before completely removing the fuel filler cap. Otherwise, fuel may
spray out and injure you or others.
If you do not use the proper fuel filler cap, excessive pressure or
vacuum in the fuel tank may damage the fuel system or cause
the fuel cap to disengage in a collision, which may result in possible
personal injury.
Choosing the right fuel
Use only UNLEADED FUEL. The use of leaded fuel is prohibited by law
and could damage your vehicle.
Do not use fuel containing methanol. It can damage critical fuel system
components.
Your vehicle was not designed to use fuel or fuel additives with metallic
compounds, including manganese-based additives. Studies indicate that
these additives can cause your vehicle’s emission control system to
deteriorate more rapidly. In Canada, many fuels contain critical fuel
system components.
Do not use fuel containing methanol. It can damage critical fuel system
components.
Repairs to correct the effects of using a fuel for which your vehicle was
not designed may not be covered by your warranty.
2004 Grand Marquis(grn)
Owners Guide (post-2002-fmt)
USA English(fus)
Maintenance and Specifications
199

Octane recommendations
Your vehicle is designed to use
“Regular”unleaded gasoline with
pump (R+M)/2 octane rating of 87.
We do not recommend the use of
gasolines labeled as“Regular”that
are sold with octane ratings of 86 or lower in high altitude areas.
Do not be concerned if your engine sometimes knocks lightly. However, if
it knocks heavily under most driving conditions while you are using fuel
with the recommended octane rating, see your dealer or a qualified
service technician to prevent any engine damage.
Fuel quality
If you are experiencing starting, rough idle or hesitation driveability
problems, try a different brand of unleaded gasoline.“Premium”
unleaded gasoline is not recommended for vehicles designed to use
“Regular”unleaded gasoline because it may cause these problems to
become more pronounced. If the problems persist, see your dealer or a
qualified service technician.
It should not be necessary to add any aftermarket products to your fuel
tank if you continue to use high quality fuel of the recommended octane
rating. Aftermarket products could cause damage to the fuel system.
Repairs to correct the effects of using an aftermarket product in your
fuel may not be covered by your warranty.
Many of the world’s automakers approved the World-wide Fuel Charter
that recommends gasoline specifications to provide improved
performance and emission control system protection for your vehicle.
Gasolines that meet the World-wide Fuel Charter should be used when
available. Ask your fuel supplier about gasolines that meet the
World-wide Fuel Charter.
Cleaner air
Ford endorses the use of reformulated“cleaner-burning”gasolines to
improve air quality.
Running out of fuel
Avoid running out of fuel because this situation may have an adverse
affect on powertrain components.
If you have run out of fuel:
•You may need to cycle the ignition from OFF to ON several times after
refueling, to allow the fuel system to pump the fuel from the tank to
the engine.
87(R+M)/2 METHOD
2004 Grand Marquis(grn)
Owners Guide (post-2002-fmt)
USA English(fus)
Maintenance and Specifications
200

•Your“Check Engine”indicator may come on. For more information on
the“Check Engine”indicator, refer to theInstrument Cluster
chapter.
Fuel Filter
For fuel filter replacement, see your dealer or a qualified service
technician. Refer to the scheduled maintenance guide for the appropriate
intervals for changing the fuel filter.
Replace the fuel filter with an authorized Motorcraft part. The
customer warranty may be void for any damage to the fuel system
if an authorized Motorcraft fuel filter is not used.
ESSENTIALS OF GOOD FUEL ECONOMY
Measuring techniques
Your best source of information about actual fuel economy is you, the
driver. You must gather information as accurately and consistently as
possible. Fuel expense, frequency of fill-ups or fuel gauge readings are
NOT accurate as a measure of fuel economy. We do not recommend
taking fuel economy measurements during the first 1,600 km (1,000 miles)
of driving (engine break-in period). You will get a more accurate
measurement after 3,000 km–5,000 km (2,000 miles-3,000 miles).
Filling the tank
The advertised fuel capacity of the fuel tank on your vehicle is equal to
the rated refill capacity of the fuel tank as listed in theRefill capacities
section of this chapter.
The advertised capacity is the amount of the indicated capacity and the
empty reserve combined. Indicated capacity is the difference in the
amount of fuel in a full tank and a tank when the fuel gauge indicates
empty. Empty reserve is the small amount of fuel remaining in the fuel
tank after the fuel gauge indicates empty.
The amount of usable fuel in the empty reserve varies and should
not be relied upon to increase driving range. When refueling your
vehicle after the fuel gauge indicates empty, you might not be
able to refuel the full amount of the advertised capacity of the
fuel tank due to the empty reserve still present in the tank.
For consistent results when filling the fuel tank:
•Turn the engine/ignition switch to the off position prior to refueling,
an error in the reading will result if the engine is left running.
2004 Grand Marquis(grn)
Owners Guide (post-2002-fmt)
USA English(fus)
Maintenance and Specifications
201

•Idling for long periods of time (greater than one minute) may waste
fuel.
•Anticipate stopping; slowing down may eliminate the need to stop.
•Sudden or hard accelerations may reduce fuel economy.
•Slow down gradually.
•Driving at reasonable speeds (traveling at 88 km/h [55 mph] uses 15%
less fuel than traveling at 105 km/h [65 mph]).
•Revving the engine before turning it off may reduce fuel economy.
•Using the air conditioner or defroster may reduce fuel economy.
•You may want to turn off the speed control in hilly terrain if
unnecessary shifting between third and fourth gear occurs.
Unnecessary shifting of this type could result in reduced fuel
economy.
•Warming up a vehicle on cold mornings is not required and may
reduce fuel economy.
•Resting your foot on the brake pedal while driving may reduce fuel
economy.
•Combine errands and minimize stop-and-go driving.
Maintenance
•Keep tires properly inflated and use only recommended size.
•Operating a vehicle with the wheels out of alignment will reduce fuel
economy.
•Use recommended engine oil. Refer toLubricant specificationsin
this chapter.
•Perform all regularly scheduled maintenance items. Follow the
recommended maintenance schedule and owner maintenance checks
found in your vehicle scheduled maintenance guide.
Conditions
•Heavily loading a vehicle or towing a trailer may reduce fuel economy
at any speed.
•Carrying unnecessary weight may reduce fuel economy (approximately
0.4 km/L [1 mpg] is lost for every 180 kg [400 lb] of weight carried).
•Adding certain accessories to your vehicle (for example bug
deflectors, rollbars/light bars, running boards, ski/luggage racks) may
reduce fuel economy.
2004 Grand Marquis(grn)
Owners Guide (post-2002-fmt)
USA English(fus)
Maintenance and Specifications
203

Do not park, idle, or drive your vehicle in dry grass or other dry
ground cover. The emission system heats up the engine
compartment and exhaust system, which can start a fire.
Illumination of the“Check Engine”light, charging system warning light
or the temperature warning light, fluid leaks, strange odors, smoke or
loss of engine power, could indicate that the emission control system is
not working properly.
Exhaust leaks may result in entry of harmful and potentially
lethal fumes into the passenger compartment.
Do not make any unauthorized changes to your vehicle or engine. By
law, vehicle owners and anyone who manufactures, repairs, services,
sells, leases, trades vehicles, or supervises a fleet of vehicles are not
permitted to intentionally remove an emission control device or prevent
it from working. Information about your vehicle’s emission system is on
the Vehicle Emission Control Information Decal located on or near the
engine. This decal identifies engine displacement and gives some tune up
specifications.
Please consult yourWarranty Guidefor complete emission warranty
information.
On board diagnostics (OBD-II)
Your vehicle is equipped with a computer that monitors the engine’s
emission control system. This system is commonly known as the On
Board Diagnostics System (OBD-II). This OBD-II system protects the
environment by ensuring that your vehicle continues to meet
government emission standards. The OBD-II system also assists the
service technician in properly servicing your vehicle. When theCheck
engine/Service engine soonlight illuminates, the OBD-II system has
detected a malfunction. Temporary malfunctions may cause yourCheck
engine/Service engine soonlight to illuminate. Examples are:
1. The vehicle has run out of fuel. (The engine may misfire or run
poorly.)
2. Poor fuel quality or water in the fuel.
3. The fuel cap may not have been securely tightened.
These temporary malfunctions can be corrected by filling the fuel tank
with good quality fuel and/or properly tightening the fuel cap. After three
driving cycles without these or any other temporary malfunctions
2004 Grand Marquis(grn)
Owners Guide (post-2002-fmt)
USA English(fus)
Maintenance and Specifications
205

present, theCheck engine/Service engine soonlight should turn off. (A
driving cycle consists of a cold engine startup followed by mixed
city/highway driving.) No additional vehicle service is required.
If theCheck engine/Service engine soonlight remains on, have your
vehicle serviced at the first available opportunity.
Readiness for Inspection/Maintenance (I/M) testing
In some localities, it may be a legal requirement to pass an I/M test of
the on-board diagnostics system. If yourCheck engine/Service engine
soonlight is on, refer to the description in theWarning lights and
chimessection of theInstrument Clusterchapter. Your vehicle may not
pass the I/M test with theCheck engine/Service engine soonlight on.
If the vehicle’s powertrain system or its battery has just been serviced,
the on-board diagnostics system is reset to a“not ready for I/M test”
condition. To ready the on-board diagnostics system for I/M testing, a
minimum of 30 minutes of city and highway driving is necessary as
described below:
•First, at least 10 minutes of driving on an expressway or highway.
•Next, at least 20 minutes driving in stop-and-go, city-type traffic with
at least four idle periods.
Allow the vehicle to sit for at least eight hours without starting the
engine. Then, start the engine and complete the above driving cycle. The
engine must warm up to its normal operating temperature. Once started,
do not turn off the engine until the above driving cycle is complete.
CHECKING AND ADDING POWER STEERING FLUID
Check the power steering fluid.
Refer to the scheduled maintenance
guide for the service interval
schedules.If adding fluid is
necessary, use only MERCON
AT F.
1. Start the engine and let it run until it reaches normal operating
temperature (the engine coolant temperature gauge indicator will be
near the center of the normal area between H and C).
2004 Grand Marquis(grn)
Owners Guide (post-2002-fmt)
USA English(fus)
Maintenance and Specifications
206