ChevroletBlazer 4WD2003Overview/chevrolet/blazer-4wd/2003/base/

2003 Chevrolet Blazer 4WD

Factory specifications, fluid capacities, torque values, EPA fuel economy and the federal safety record for the 2003 Blazer 4WD.

Body SUVTransmission Automatic 4-spd

The 2003 Chevrolet Blazer 4WD is a sport‑utility vehicle that takes 4.5 quarts of 5W‑30 API‑classified engine oil and is paired with a four‑speed automatic transmission, delivering EPA‑rated fuel economy of 20 mpg city, 23 mpg highway and 21 mpg combined. With 104 owner‑reported complaints—most frequently concerning the air‑bag system—and a single recall, this model year sits well below the 1995 peak of 1,418 complaints but above the 2005 low of 15, reflecting a period of improving reliability within the Blazer’s 1990‑2005 timeline.

Model year200319961989

Quick specs

Fluid capacities, tune-up values and fuel economy at a glance.

Engine oil capacity4.5 qtOEM · verified
Engine oil type5W-30 APIOEM · verified
Lug nut torque100 ft-lbsOEM · verified
EPA fuel economy20/23/21 mpgEPA · verified

Fitment & sizes

Replacement part sizes and factory part numbers — battery, bulbs, filters and belts.

From the factory this vehicle uses a BCI 75 · 525 CCA battery, OE oil filter 19210286. Each part links to every other vehicle that shares it, so a part you already stock may fit more of your fleet than you'd expect.

Battery groupBCI 75 · 525 CCAOEM · verified
Tire sizeP245-70R16OEM · verified
Wheel / rim7-J inOEM · verified

OE service part numbers OEM · verified

Engine oil filter19210286 alt 12731175
Engine air filter25170512 alt 19259086
Fuel filter25168594
Spark plug12681665
Front wiper blades15757007 alt 15757008
Serpentine belt12576453 alt 19355374
Thermostat12632948 alt 12551507

Full specifications

Engine, drivetrain, dimensions and economy.

Engine & drivetrain NHTSA vPIC

TransmissionAutomatic 4-spd

Dimensions & weight NHTSA vPIC

Overall length176.8 in
Overall width67.7 in
Overall height65 in
Wheelbase100.4 in
Curb weight3516 lb
Track (front / rear)54.7 / 54.7 in
Weight distribution (front / rear)55/45

Ratings & economy EPA / vPIC

EPA city / highway / combined20 / 23 / 21 mpg
Drivetrain4-Wheel or All-Wheel Drive
Recommended fuelRegular Gasoline

Service quick specs OEM factory data

Capacities, torques and tune-up values from the factory service manual.

This engine holds 4.5 qt of 5W-30 API engine oil, DOT 3 brake fluid. Torque lug nuts to 100 ft-lbs, the oil drain plug to 18.0 ft-lbs. The firing order is 1-6-5-4-3-2.

Lubricants & capacities

Brake FluidDOT 3
Engine Oil5W-30 · API
Engine Oil Capacity4.5 qt

Engine torques

Crankshaft Pulley and/or Damper Bolts70 ft-lbs
Engine Oil Pan Drain Plug18.0 ft-lbs
Engine Valve Cover Bolts8.85 ft-lbs

Chassis torques

Leaf Spring to Axle (U-bolts)74.0 ft-lbs
Leaf Spring to Chassis Bracket89.0 ft-lbs
Leaf Spring to Rear Shackle89.0 ft-lbs
Leaf Spring Rear Shackle to Chassis Bracket89.0 ft-lbs
Lug Nuts100 ft-lbs
Transfer Case Fill Plug18.0-30.0 ft-lbs
Transfer Case Drain Plug18.0-30.0 ft-lbs
Front Wheel Hub103 ft-lbs

Ignition

Cylinder Firing Order1-6-5-4-3-2
Spark Plug ManufacturerAC Delco
Spark Plug Gap0.060 in
Spark Plug Torque11-14 ft-lbs

Battery & A/C

RefrigerantR134a
Refrigerant Capacity1.75-2.00 lbs
Oil GroupPAG
Oil Capacity8.00 oz
Oil Type46
Standard BCI Group Number75
Standard BCI Cranking Performance525 cca
Optional BCI Group Number75

Service checks

Pressure Test20 psi
Radiator Cap Pressure Relief15 psi
Thermostat Opening Temperature188-206 °F
Fuel Pump Pressure Minimum62.0 psi
Key ON Engine OFF (KOEO)55-62
RPM45-59 @ Idle rpm
Injector Primary Resistance11-14 @ 50-90 degreesF ohms
Engine Compression100

Brakes

Brake ApplicationWITH FOUR WHEEL DISC / WITH STANDARD
Torque to Knuckle77 ft-lbs / 52 ft-lbs / 38 ft-lbs
Minimum Pad ThicknessFront: 0.030; Rear: 0.030 specification
Brake ApplicationWITH FOUR WHEEL DISC / WITH STANDARD
Rotor Max Parallel Variation0.001 in
Rotor Runout Limit0.002 in
Rotor Nominal Thickness From1.14 in / 0.787 in / 1.03 in
Rotor Nominal Thickness To1.14 in / 0.787 in / 1.03 in

Factory maintenance schedule OEM · verified

Normal service, condensed from the factory interval matrix.

Under the factory schedule, replace the engine oil and filter every 7,500 mi; spark plugs every 100,000 mi; coolant at 150,000 mi. The big-interval services (at 150,000 mi for coolant, and the transmission fluid) are the ones owners most often skip — on a lower-mileage example, assume the original fluids are still in it and check them first.

At 7,500 miDrive Axle Assembly (drain & refill)
Every 7,500 miAxle Shaft Oil Seal (inspect) · CV Joint Boot (inspect) · Differential (inspect fluid level) · Engine Oil (drain & refill) · Engine Oil Filter (replace) · Tire & Wheel Assembly (rotate)
At 15,000 miEngine Air Filter Element (inspect)
Every 30,000 miEngine Air Filter Element (inspect) · Engine Air Filter Element (replace) · Fuel Filter (replace)
Every 50,000 miTransfer Case Assembly (drain & refill) · Transmission Fluid & Filter (replace)
Every 100,000 miPCV Valve (inspect) · Spark Plug Wires (inspect) · Spark Plugs (replace)
At 150,000 miAccessory Drive Belt (inspect) · Engine Coolant System (drain, flush & refill)

Reliability & federal safety record

Owner-reported issues, recalls, investigations and service bulletins on record with NHTSA — an unfiltered look at what owners actually experience.

Owner complaints about the 2003 Chevrolet Blazer 4WD top in one area — the air bags, 13 of 104 reports (12%), well ahead of the next concern. None of this vehicle's 1 recall campaigns target the air bags, so those reports read as owner-reported wear-and-tear rather than an acknowledged defect. 15 of the reports describe a crash and 0 a fire — a small share of the total, but worth weighing against the air bags pattern above. These are tallies of what owners actually reported to the federal government, not an editorial score — and higher-selling models naturally rack up more reports.

1
Open recalls
NHTSA campaigns
424
Service bulletins
Manufacturer communications
0
ODI investigations
Office of Defects Investigation
104
Owner complaints
15 involved a crash · 0 a fire
NHTSA crash-test rating federal NCAP · out of 5 stars
Rollover★★★★★
Owner complaints by model year NHTSA · this generation & adjacent

Owner complaints filed with NHTSA, by component

All 104 complaints on record, top 8 components.

Air Bags13
Electrical System12
Power Train11
Structure9
Fuel System, Gasoline7
Engine & Engine Cooling5
Exterior Lighting5
Visibility3

Source: NHTSA Office of Defects Investigation complaint database.

Recalls NHTSA · verified

Showing 1 of 1 campaigns on record for this vehicle.

04V132000Equipment:Other:LabelsReported 18/03/2004

CERTAIN PICKUP TRUCKS AND SPORT UTILITY VEHICLES FAIL TO COMPLY WITH THE REQUIREMENTS OF FEDERAL MOTOR VEHICLE SAFETY STANDARD NO. 208, "OCCUPANT CRASH PROTECTION." Remedy: OWNERS WILL BE PROVIDED WITH CORRECT LABELS AND INSTALLATION INSTRUCTIONS. OWNER NOTIFICATION BEGAN ON JUNE 4, 2004. OWNERS SHOULD CONTACT CHEVROLET AT 1-800-630-2438 OR GMC AT…

Technical service bulletins NHTSA · verified

Showing 5 of 424 bulletins on record with NHTSA.

BulletinDateComponentSummary
PIP5601C2025-07-18Unknown Or OtherThis PI communicates the requirement to provide a pico file to receive diagnostic…
PIP5358D2025-02-19Unknown Or OtherThis Preliminary Information communication provides information to the technician about…
PIP4723J2024-10-25Electrical SystemThis Preliminary Information communicates to the dealer the process for downloading or…
PIT5099H2024-09-12Unknown Or OtherThis Preliminary Information communication provides information to the technician about…
PIT5099H2024-09-12Unknown Or OtherThis Preliminary Information communication provides information to the technician about…

Common OBD-II trouble codes

The most common OBD-II codes for this vehicle's emissions system. These are standardized SAE J2012 definitions, not vehicle-specific fault reports.

P0420
Catalyst system efficiency below threshold — Bank 1
P0300
Random / multiple cylinder misfire detected
P0171
System too lean — Bank 1
P0455
Evaporative emission system leak detected — large leak
P0128
Coolant thermostat below regulating temperature
P0442
Evaporative emission system leak detected — small leak

VIN tools

Decode factory build data for a specific vehicle by VIN.

VIN
Decode a VIN to confirm the transmission and build data for a specific Blazer 4WD. OEM
Build data
Plant, GVWR class, engine and body data for any 17-character VIN.
Recalls
Check open recall campaigns against a specific vehicle by VIN.

Vehicles with shared specs

Find every vehicle that shares this one's battery, bulbs, oil capacity, platform or parts.

Reference guides

Cross-vehicle references for the kinds of data on this page.

Frequently asked

How much oil does the 2003 Blazer 4WD take?

4.5 qt of 5W-30 API, per the factory manual.

Does the 2003 Blazer 4WD have open recalls?

NHTSA lists 1 recall campaign(s) for this model year. Check your specific vehicle by VIN.

What gas mileage does the Blazer 4WD get?

EPA figures are 20 city / 23 highway / 21 combined mpg.