2003 BUICK REGAL engine

Underhood Fuse Block
Some fuses and relays are located in the underhood
fuse block on the passenger’s side of the vehicle in the
engine compartment. SeeEngine Compartment
Overview on page 5-10or more information on location.
Fuses Usage
1 Anti-Lock Brake System
2 Starter Solenoid
3Power Seats, Rear Window
Defogger Heated Seats
4High Blower, Hazard Flasher,
Stoplamps, Power Mirror, Door
Locks
5Ignition Switch, BTSI, Stoplamps,
Anti-Lock Brake System, Turn
Signals, Cluster, Air Bag, Daytime
Running Lamps Module
6 Cooling Fan
7Retained Accessory Power, Keyless
Entry, Data Link, Heating Ventilation
Air Conditioning Head, Cluster,
Radio, Auxiliary Power (Power
Drop), Cigarette Lighter
8Ignition Switch, Wipers, Radio,
Steering Wheel Controls, Body
Control Module, Auxiliary Power
(Power Drop), Power Windows,
Sunroof, Heating Ventilation Air
Conditioning Controls, Daytime
Running Lamps, Rear Window
Defogger Relay
5-90
2003 - Regal OM

Relays Usage
9 Cooling Fan 2
10 Cooling Fan 3
11 Starter Solenoid
12 Cooling Fan 1
13 Ignition Main
14 Air Pump (Optional)
15 Not Used
16 Horn
17 Fog Lamps
18 Not Used
19 Fuel Pump
Fuses Usage
20 Not Used
21 Generator
22 Engine Control Module
23 A/C Compressor Clutch
24 Cooling Fan
25 Electronic Ignition
Fuses Usage
26 Transaxle
27 Horn
28 Fuel Injector
29 Oxygen Sensor
30 Engine Emissions
31 Fog Lamps
32 Headlamp (Right)
33 Rear Compartment Release
34 Parking Lamps
35 Fuel Pump
36 Headlamp (Left)
37 Not Used
38 Not Used
39 Not Used
40 Not Used
41 Not Used
42 Not Used
43 Not Used
SYMBOL A/C Compressor Clutch Diode
5-91
2003 - Regal OM

Capacities and Specications
Capacities and Specications
ApplicationCapacities
English Metric
Air Conditioning Refrigerant R134a 2.4 lbs 1.1 kg
Automatic Transaxle
Pan Removal and Replacement
After Complete Overhaul
When draining/replacing converter, morefluid will be needed.7.4 quarts
10.0 quarts7.0 L
9.5 L
Cooling System Including Reservoir 11.7 quarts 11.0 L
Engine Oil with Filter 4.5 quarts 4.3 L
Fuel Tank 17.0 gallons 64.0 L
Wheel Nut Torque 100 lb ft 140Y
All capacities are approximate. When adding, be sure tofill to the approximate level, as recommended in this
manual. SeePart D: Recommended Fluids and Lubricants on page 6-16.
Engine Specications
Engine VIN Code Displacement Firing Order
3800 V6
3800 Supercharged V6K
1231 CID 1–6–5–4–3–2
5-92
2003 - Regal OM

Normal Maintenance Replacement Parts
Part Number
Engine Air Cleaner/FilterA1614C*
Engine Oil FilterType PF47*
Passenger Compartment Air Filter10406026
Spark Plugs
3800 V6Type 41–101*
Gap: 0.060 inches (1.52 mm)
3800 Supercharged V6Type 41–101*
Gap: 0.060 inches (1.52 mm)
Wiper Blade
Type
LengthShepherd’s Hook
22.0 inches (56.0 cm)
*ACDelco
®part number.
5-93
2003 - Regal OM

Maintenance Schedule......................................6-2
Introduction...................................................6-2
Your Vehicle and the Environment....................6-2
Maintenance Requirements..............................6-2
How This Section is Organized.........................6-3
Part A: Scheduled Maintenance Services...........6-4
Using Your Maintenance Schedule....................6-4
Scheduled Maintenance...................................6-4
Part B: Owner Checks and Services................6-10
At Each Fuel Fill..........................................6-10
At Least Once a Month.................................6-10
At Least Twice a Year...................................6-11At Least Once a Year...................................6-11
Part C: Periodic Maintenance Inspections.........6-14
Steering, Suspension and Front Drive Axle
Boot and Seal Inspection............................6-14
Exhaust System Inspection............................6-14
Fuel System Inspection..................................6-15
Engine Cooling System Inspection...................6-15
Throttle System Inspection.............................6-15
Brake System Inspection................................6-15
Part D: Recommended Fluids and Lubricants. . . .6-16
Part E: Maintenance Record...........................6-17
Section 6 Maintenance Schedule
6-1
2003 - Regal OM

Maintenance Schedule
Introduction
Important: Keep engine oil at the proper level and
change as recommended.
Have you purchased the GM Protection Plan? The Plan
supplements your new vehicle warranties. See your
Warranty and Owner Assistance booklet or your dealer
for details.
Your Vehicle and the Environment
Proper vehicle maintenance not only helps to keep your
vehicle in good working condition, but also helps the
environment. Improper vehicle maintenance can
even affect the quality of the air we breathe. Improper
fluid levels or the wrong tire inflation can increase
the level of emissions from your vehicle. To help protect
our environment, and to keep your vehicle in good
condition, be sure to maintain your vehicle properly.
Maintenance Requirements
Maintenance intervals, checks, inspections and
recommended fluids and lubricants as prescribed in this
manual are necessary to keep your vehicle in good
working condition. Any damage caused by failure
to follow scheduled maintenance may not be covered by
warranty.
6-2
2003 - Regal OM

Part A: Scheduled Maintenance
Services
This part contains engine oil scheduled maintenance
which explains the engine oil life system and how
it indicates when to change the engine oil andfilter.
Also, listed are scheduled maintenance services which
are to be performed at the mileage intervals specified.
Using Your Maintenance Schedule
We at General Motors want to keep your vehicle in good
working condition. But we don’t know exactly how
you’ll drive it. You may drive short distances only a few
times a week. Or you may drive long distances all
the time in very hot, dusty weather. You may use your
vehicle in making deliveries. Or you may drive it to
work, to do errands or in many other ways.
Because of the different ways people use their vehicles,
maintenance needs may vary. You may need more
frequent checks and replacements. So please read the
following and note how you drive. If you have
questions on how to keep your vehicle in good condition,
see your dealer.
This part tells you the maintenance services you should
have done and when to schedule them.
When you go to your dealer for your service needs,
you’ll know that GM-trained and supported service
people will perform the work using genuine GM parts.The properfluids and lubricants to use are listed in
Part D. Make sure whoever services your vehicle uses
these. All parts should be replaced and all necessary
repairs done before you or anyone else drives the
vehicle.
This schedule is for vehicles that:
•carry passengers and cargo within recommended
limits. You willfind these on your vehicle’s
Tire-Loading Information label. SeeLoading Your
Vehicle on page 4-33.
•are driven on reasonable road surfaces within legal
driving limits.
•use the recommended fuel. SeeGasoline Octane
on page 5-4.
Scheduled Maintenance
The services shown in this schedule up to 100,000 miles
(166 000 km) should be repeated after 100,000 miles
(166 000 km) at the same intervals for the life of
this vehicle. The services shown at 150,000 miles
(240 000 km) should be repeated at the same interval
after 150,000 miles (240 000 km) for the life of this
vehicle.
SeePart B: Owner Checks and Services on page 6-10
andPart C: Periodic Maintenance Inspections on
page 6-14.
6-4
2003 - Regal OM

Footnotes
†The U.S. Environmental Protection Agency or the
California Air Resources Board has determined that the
failure to perform this maintenance item will not nullify
the emission warranty or limit recall liability prior to
the completion of the vehicle ’s useful life. We, however,
urge that all recommended maintenance services be
performed at the indicated intervals and the
maintenance be recorded.
@Whenever the tires are rotated, the Tire Ination
Monitor System must be reset.
+A good time to check your brakes is during tire
rotation. See Brake System Inspection on page 6-15.
Engine Oil Scheduled Maintenance
Change engine oil and filter as indicated by the
GM Oil Life System (or every 12 months, whichever
occurs first). Reset the system.
Your vehicle has a computer system that lets you know
when to change the engine oil andfilter. This is
based on engine revolutions and engine temperature,
and not on mileage. Based on driving conditions,
the mileage at which an oil change will be indicated can
vary considerably. For the oil life system to work
properly, you must reset the system every time the oil is
changed.When the system has calculated that oil life has been
diminished, it will indicate that an oil change is
necessary. A CHANGE OIL SOON light will come on.
Change your oil as soon as possible within the next two
times you stop for fuel. It is possible that, if you are
driving under the best conditions, the oil life system may
not indicate that an oil change is necessary for over a
year. However, your engine oil andfilter must be
changed at least once a year and at this time the system
must be reset. Your dealer has GM-trained service
people who will perform this work using genuine GM
parts and reset the system.
It is also important to check your oil regularly and keep
it at the proper level.
If the system is ever reset accidentally, you must
change your oil at 3,000 miles (5 000 km) since your
last oil change. Remember to reset the oil life system
whenever the oil is changed. SeeEngine Oil on
page 5-13for information on resetting the system.
An Emission Control Service.
See the mileage intervals following for additional
services that may be performed with an engine oil
change. After the services are performed, record the
date, odometer reading and who performed the service
on the maintenance record pages in Part E of this
schedule.
6-5
2003 - Regal OM