2003 FORD THUNDERBIRD check engine

For vehicles with overflow coolant systems with a non-pressurized cap
on the coolant recovery system, add coolant to the coolant recovery
reservoir when the engine is cool. Add the proper mixture of coolant and
water to the“cold full”level. For all other vehicles, which have a coolant
degas system with a pressurized cap, or if it is necessary to remove the
coolant pressure relief cap on the radiator of a vehicle with an overflow
system, follow these steps to add engine coolant.
To reduce the risk of personal injury, make sure the engine is
cool before unscrewing the coolant pressure relief cap. The
cooling system is under pressure; steam and hot liquid can come out
forcefully when the cap is loosened slightly.
1. Before you begin, turn the engine off and let it cool.
2. When the engine is cool, wrap a thick cloth around the coolant
pressure relief cap on the coolant reservoir (an opaque plastic bottle).
Slowly turn cap counterclockwise (left) until pressure begins to release.
3. Step back while the pressure releases.
4. When you are sure that all the pressure has been released, use the
cloth to turn it counterclockwise and remove the cap.
5. Fill the coolant reservoir slowly with the proper coolant mixture (see
above), to within the“cold fill range”or the“cold full”level on the
reservoir. If you removed the radiator cap in an overflow system, fill the
radiator until the coolant is visible and radiator is almost full.
6. Replace the cap. Turn until tightly installed. (Cap must be tightly
installed to prevent coolant loss.)
After any coolant has been added, check the coolant concentration, refer
toChecking Engine Coolantsection. If the concentration is not 50/50
(protection to–34°F/–36°C), drain some coolant and adjust the
concentration. It may take several drains and additions to obtain a 50/50
coolant concentration.
Whenever coolant has been added, the coolant level in the coolant
reservoir should be checked the next few times you drive the vehicle. If
necessary, add enough 50/50 concentration of engine coolant and
distilled water to bring the liquid level to the proper level.
If you have to add more than 1.0 liter (1.0 quart) of engine coolant per
month, have your dealer check the engine cooling system. Your cooling
system may have a leak. Operating an engine with a low level of coolant
can result in engine overheating and possible engine damage.
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164

How fail-safe cooling works
If the engine begins to overheat:
•The engine coolant temperature
gauge will move to the H (hot)
area.
•The
symbol will
illuminate.
•The
symbol will illuminate.
•The
symbol will illuminate.
If the engine reaches a preset over-temperature condition, the engine
will automatically switch to alternating cylinder operation. Each disabled
cylinder acts as an air pump and cools the engine.
When this occurs the vehicle will still operate. However:
•The engine power will be limited.
•The air conditioning system will be disabled.
Continued operation will increase the engine temperature and 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.
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166

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.
If the“Check Fuel Cap”indicator comes on and stays on after you start
the engine, the fuel filler cap may not be properly installed. Turn off the
engine, remove the fuel filler cap, align the cap properly and reinstall it.
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 compounds containing MMT.
Repairs to correct the effects of using a fuel for which your vehicle was
not designed may not be covered by your warranty.
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169

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.
•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
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171

Habits
•Smooth, moderate operation can yield up to 10% savings in fuel.
•Steady speeds without stopping will usually give the best fuel
economy.
•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 fourth and fifth 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).
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173

If other than Ford, Motorcraft or Ford-authorized parts are used for
maintenance replacements or for service of components affecting
emission control, such non-Ford parts should be equivalent to genuine
Ford Motor Company parts in performance and durability.
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.
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 your“Check Engine/Service Engine
Soon”light is on, refer to the description in theWarning lights and
chimessection of theInstrument clusterchapter. Your vehicle may not
pass the I/M test with the“Check Engine/Service Engine Soon”light 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.
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175

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.
POWER STEERING FLUID
Refer to the scheduled maintenance guide for the service interval
schedules. If adding fluid is necessary, use only MERCONAT 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).
2. While the engine idles, turn the
steering wheel left and right several
times.
3. Turn the engine off.
4. Check the fluid level in the
reservoir. It should be between the
MIN and MAX lines. Do not add
fluid if the level is in this range.
5. If the fluid is low, add fluid in
small amounts, continuously
checking the level until it reaches
the range between the MIN and
MAX lines. Be sure to put the cap
back on the reservoir.
BRAKE FLUID RESERVOIR
The fluid level will drop slowly as
the brakes wear, and will rise when
the brake components are replaced.
Fluid levels between the“MIN”and
“MAX”lines are within the normal
operating range, there is no need to
add fluid. If the fluid levels are
outside of the normal operating range, the performance of your brake
system could be compromised, seek service from your dealer
immediately.
MAX
MIN
MAX
MIN
M
A
X
M
IN
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176

TRANSMISSION FLUID
Checking automatic transmission fluid
The 5R55S transmission does not have a transmission fluid dipstick.
Refer to your scheduled maintenance guide for scheduled intervals for
fluid checks and changes. Your transmission does not consume fluid.
However, the fluid level should be checked if the transmission is not
working properly, i.e., if the transmission slips or shifts slowly or if you
notice some sign of fluid leakage.
Transmission fluid should be checked and, if required, fluid
should be added by a qualified technician.
Before adding any fluid, make sure the correct type is used. Use only
MERCONV automatic transmission fluid. The type of fluid used is
indicated on the transmission fluid pan, extension housing and also in
theLubricant specificationssection in this chapter.
Use of a non-approved automatic transmission fluid may cause
internal transmission component damage and void the warranty.
Do not use supplemental transmission fluid additives, treatments or
cleaning agents. The use of these materials may affect transmission
operation and result in damage to internal transmission components.
AIR FILTER MAINTENANCE
Refer to the scheduled maintenance guide for the appropriate intervals
for changing the air filter element.
When changing the air filter element, use only the Motorcraft air filter
element listed. Refer toMotorcraft Part Numbers.
Note:Do not start your engine with the air cleaner removed and do not
remove it while the engine is running.
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177