2003 Chevrolet Trailblazer Ext Engine Cooling Parts

Please Select your Vehicle to See Exact Fit Parts

Keep Your 2003 Chevrolet Trailblazer Ext in Top Shape with Quality Engine Cooling Parts

Whether you’re repairing or upgrading your Engine Cooling Part, using high-quality parts is key to keeping your 2003 Chevrolet Trailblazer Ext looking sharp and performing at its best. At Advance Auto Parts we carry a wide selection of dependable options, including Thermostats, Water Pumps, and Radiators. Whether you’re replacing a damaged part or enhancing your truck’s style and protection, you’ll find exactly what you need to get the job done right.

Top-Rated Engine Cooling Parts from Trusted Brands

Looking for a reliable Engine Cooling Part? We’ve got you covered with options from brands you know and trust like Felpro, Carquest Premium, and Dorman. For example, Felpro Engine Cooling Parts start at just $5.79 with an average 4.6 star rating. Carquest Premium and Dorman offer similar pricing and quality, backed by strong customer feedback. With over 5,622 reviews and a solid 4 star average, you can shop with confidence knowing other Chevrolet Trailblazer Ext owners approve.

Competitive Prices and Extensive Inventory

The average price for a 2003 Chevrolet Trailblazer Ext Engine Cooling Part at Advance Auto Parts is around $75.97, with a range that starts at $3.29 and goes up to $341.99. With 71 options in stock from 19 trusted brands, finding the right fit is easy. Popular picks like Engine Water Pump, Engine Water Pump Gasket, and Radiator Cap: 15 PSI start at just $7.49 and offer a great balance of form and function.

Explore Related Parts

While you’re upgrading or replacing your Engine Cooling Part, don’t forget to check out other key components like Blower Motor and Related Products and HVAC Electrical Parts. At Advance Auto Parts, we’re here to help you keep your 2003 Chevrolet Trailblazer Ext in peak condition, inside and out.

Looking for the perfect Engine Cooling Part for your 2003 Chevrolet Trailblazer Ext? You’re in the right place. Below, you’ll find links to various types of Engine Cooling Parts that fit your vehicle. At Advance Auto Parts, we offer only the highest quality OEM and aftermarket Engine Cooling Parts, ensuring durability and a precise fit for your Chevrolet Trailblazer Ext. Whether you’re driving a 2003 model or another popular model year like 2002, 2004, 2005, and 2006, we’ve got you covered. Purchasing Engine Cooling Parts from Advance Auto Parts is a smart choice, giving you access to trusted brands and parts built to perform. Below, you’ll find links to various types of Engine Cooling Parts that fit your vehicle.

Essential 2003 Chevrolet Trailblazer Ext Engine Cooling Parts

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$12.99

Cracked or lost the original engine coolant reservoir cap- Replace it seamlessly and effectively with this precisely engineered, direct replacement cap.

Product Features:

Direct replacement – this engine coolant reservoir cap directly replaces a cracked or lost original cap
Application specific – made to match dimensions of reservoir cap on only certain vehicle years, makes and models
Seamless fit – reverse-engineered from the original equipment to fit perfectly
Excellent value – a quick, easy replacement that’s less expensive than going back to the dealership

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$71.99

This premium water pump uses new high-quality components and is designed to meet or exceed OE specifications. This pump is 100% tested to ensure quality. Bearings, gaskets, seals, impeller, hub and housing are all designed for long-lasting service life. All necessary gaskets and seals are included.

Product Features:

Built to meet or exceed OE fit, form and function
All components necessary for installation are supplied with pump
100% tested for reliable performance
Follow all enclosed instructions to maximize pump life and validate warranty
Additional Notes: Includes gasket

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$56.99

The fastest, easiest way to know exactly when it’s safe to open your radiator cap. ThermoCap, with its built-in calibrated thermometer, indicates the coolant temperature.

Product Features:

Indicates coolant temperature
Helps prevent coolant injuries
Fahrenheit and centigrade readings
Color-coded temperature ranges
Integrated coolant reclamation valve
Improves under-hood appearance
Chromed crown with a colored trim ring

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$3.29

Fel-Pro® gaskets are specifically designed for the repair environment to deliver a reliable seal on even the most troublesome applications. Designed for imperfect sealing surfaces and manufactured with proprietary materials, you can count on Fel-Pro for innovative sealing solutions for the real-world repair environment.

Product Features:

Meets or exceeds all original equipment specifications
Application specific design to ensure a perfect fit
Engineered and manufactured specifically for the repair environment
Unsurpassed quality you can trust
Each Fel-Pro gasket, no matter how small, is engineered to exacting standards with proprietary design, engineering and manufacturing processes

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$19.99

The engine cooling system is critical to engine sustainability under all operating conditions. The Coolant Level Sensor reports the level of coolant either in the radiator overflow container or in the radiator tank.

Product Features:

Product constructed to meet all design and operating characteristics as intended by the vehicle manufacturer.
Computer-Aided Design (CAD), laser scanning and 3D printing – utilizing Fused Deposition Modeling (FDM) and Stereolithography (SLA) – in the part design process ensures speed-to-market and a precise fit guaranteed.
Tin plated lead frame prevents corrosion and ensures a reliable terminal connection under adverse ambient conditions.
100% thermo-shock and vibration tested to ensure superior performance in extreme conditions.
100% end-of-line tested to ensure accurate signal output providing product reliability, every time.

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$44.99

This engine cooling fan motor connector is designed to match the appearance and function of the original hardware on specified applications. Made of quality materials, it is engineered for reliable performance and durability.

Product Features:

Direct replacement – this engine cooling fan motor connector matches the appearance and function of the factory hardware on specified applications
Ideal solution – this connector is a reliable replacement for an original part that is missing or has failed due to fatigue
Durable construction – this part is made from quality materials to ensure reliable performance and Length service life
Trustworthy quality – backed by team of product experts in the United States and more than a century of automotive experience

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$39.99

We are proud to offer this Carquest product line: Carquest Water Outlets. Our products are engineered and tested to provide years of trouble free operation and designed to be hassle free OE replacement part that meets and/or exceeds OE standards. Backed by over 50 years of mobile temperature control experience, fix it once and fix it right with CARQUST Water Outlets and Thermostat Housings.

Product Features:

Meets and/or exceeds OEM standard
Direct-fit replacement for ease of installation
100% leak tested
Meets and/or exceeds OEM standard
100% leak tested
Direct-fit replacement for ease of installation

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$93.99

This replacement engine coolant pipe assembly is designed to match the fit and function of the original assembly on specified makes, years and models, and is engineered for reliable performance and durability.

Product Features:

Direct replacement – this replacement engine coolant pipe assembly is designed to match the fit and function of the original assembly on specified makes, years and models
Restores functionality – reliable replacement for an original part that is leaking, cracked or failed from corrosion and heat
Durable construction – this part is made from quality materials to ensure reliable performance and long service life
Trustworthy quality – backed by team of product experts in the United States and more than a century of automotive experience

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$37.99

Designed to open at 180 degrees every time, regardless of engine rpm, and it’s high-flow design and brass and copper construction eliminate the damaging effects of cycling when you’re stuck in stop-and-go traffic. It includes the rubber gasket and has a pressure relief valve.

Product Features:

Opens sooner than stock at 180 degrees
High flow design for performance applications
Includes rubber o-ring seal/gasket
Incorporates pressure relief valve

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$64.99

Mr. Gasket Swivel Water Necks are great for engine conversion applications where engine/radiator inlet and outlet ports may be in different locations versus original equipment. The outlet rotates 360 degrees and has a 30 degree angle for versatility. Die-cast aluminum construction is strong, and durably resisting corrosion and is chrome plated for classic looks. It has a thick mounting flange to prevent warping and provide a positive engine coolant seal. Included stainless steel Allen head cap screws mount flush with the top of the flange to provide a smooth, custom look. Designed for use with 1/2 inch radiator hoses.

Product Features:

Neck rotates 360 degrees 30 degree angle for maximum versatility in engine swaps
Die-cast aluminum for strength and durability and resist corrosion
Thick mounting flange prevents warping and provides a positive coolant seal
Chrome-plated for looks
Allen head stainless steel bolt mount flush to flange for custom look
Uses commonly available 1-1/2 radiator hose (casting I.D 1-3/16″)

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$52.99

GM Genuine Parts Wiring Relays are designed, engineered, and tested to rigorous standards, and are backed by General Motors. These relays help connect or disconnect power to a vehicle accessory when it receives a low voltage signal from a switch. GM Genuine Parts are the true OE parts installed during the production of or validated by General Motors for GM vehicles. Some GM Genuine Parts may have formerly appeared as ACDelco GM Original Equipment (OE).

Product Features:

Helps connect or disconnect power to vehicle accessories
Some GM Genuine Parts may have formerly appeared as ACDelco GM Original Equipment (OE)
GM Genuine Parts are designed, engineered and tested to rigorous standards, and are backed by General Motors
GM Engineers design and validate OE parts specifically for your Chevrolet, Buick, GMC, or Cadillac vehicle
GM regularly updates production and service part designs to integrate new materials and technologies

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$5.79

Fel-Pro gaskets offer 100% vehicle sealing with application-specific materials to give you sealing solutions with the performance and durability professionals trust.

Product Features:

Meets or exceeds all original equipment specifications
Application specific design
Manufactured for the sealing repair environment
Validated for fit, form, and function
Quality that you can trust

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$188.99

US Motor Works Professional Series Water Pump with Fan Clutch are designed to replace the mechanical components of a cooling system. A proper water pump replacement should include a new fan clutch as the two are connected to the same shaft and work together to move the air and cooling fluid. Replacing one without the other can damage the new part and cause repeat work or engine trouble. This matched set will allow your vehicle continued operation in the demanding environment of today’s engine. All components are brand new and QA inspected for perfect fit and function. Restore your cooling power by installing a US Motor Works Professional Series Water Pump with Fan Clutch.

Product Features:

Fan clutch mounts to the water pump and should be replaced at the same time.
Matched set for proper water pump or fan clutch replacement
Includes mounting hardware, gaskets and accessories as required.
Complete mechanical cooling parts replacement
Factory tested and 100% new product
Meets or exceeds OEM quality

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$341.99

Carquest Premium Radiators offer one of the largest product ranges in the aftermarket, covering more than 95% of the popular automotive and light truck applications. Carquest Premium Radiators meet or exceed original equipment specifications, ensuring that products fit and perform just as well or better than the original parts, providing you peace of mind.

Product Features:

Our B-type tubes feature central reinforcement to provide greater tolerance to pressure. Stronger tube design means drastically reduced probability of tube failure.
Our deep extrusion header provides a stronger tube to header joint which is more resistant to the effects of vibration and thermal tube expansion, virtually eliminating tube to header leaks.
Our fin edges are folded for increased stability and heat disbursement properties.
Our included “multi-fit” attachments allow one radiator to cover multiple vehicle applications without sacrificing OE fit. This results in wider vehicle coverage with substantially less inventory.
Thermal expansion cuts allow for longer life and reduce failure rates by allowing improved core expansion and contraction during normal heat cycles.
We design and manufacture all our radiators to meet or even exceed Original Equipment specifications. We take pride in producing the most reliable replacement parts in the market.
We use longer header tabs for increased pressure resistance. This reduces the potential for tank to header leaks.

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$70.99

Product Features:

Eliminates trapped air, hot spots, and overheating
Use w/ Stock Factory Style Intake Manifold and Stock Steam Cross-Over Tube
Includes Black Hose, 90 Degree Hose End, 1/8″ NPT Adapter & Clamp
Hose Length: 4 Feet of 1/4″ Hose – Can be Cut to Desired Length
Ideal for use with Holley LS Mid-Mount Accessory Drive Systems, but also works with many other LS engine conversions.

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$4.99

Fel-Pro gaskets offer 100% vehicle sealing with application-specific materials to give you sealing solutions with the performance and durability professionals trust.

Product Features:

Meets or exceeds all original equipment specifications
Application specific design to ensure a perfect fit
Engineered and manufactured specifically for the repair environment
Unsurpassed quality you can trust
Validated for fit, form, and function

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$229.99

Please note: Advance Auto Parts is proud to carry comparable exact-fit parts from multiple vendors, as such, the item you receive may be one of two quality brands. Both brands meet the same fitment requirements and are equal in their performance and specifications. The fan clutch is the component of the cooling system that varies the fan speed to meet the cooling needs of the engine. The fan clutch provides high airflow volume and, by only operating the fan as needed, promotes good fuel economy. CARQUEST fan clutches are designed to meet OE performance specifications.

Product Features:

Designed, tested, and built by application
OE performance, fit, and appearance
Precision machined
Out of box installation
Designed, tested, and built by application
OE performance, fit, and appearance
Precision machined
Out of box installation

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$51.99

This replacement engine coolant reservoir is manufactured from quality materials to withstand the stresses of underhood heat and engine vibration. It is engineered and manufactured to match the fit and function of the original part.

Product Features:

Direct replacement – this engine coolant reservoir matches the fit and function of the original part
Ideal solution – engineered for a seamless installation
Durable construction – manufactured from quality materials to withstand underhood heat and vibration
Trustworthy design – backed by 100 years of automotive aftermarket experience

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$39.49

Carquest Premium Integrated Housing Thermostats are manufactured with OEM quality materials and safety standards by an OE Supplier. This integrated thermostat housing will meet and exceed the expectations of the OE thermostat to insure the best product for your cooling system. Stands up to even the most demanding automotive cooling systems. Manufactured with OEM specifications and processes. Copper case and wax compound assures rapid response to temperature changes in the coolant as well as the design and function of the housing. Offset design, air relief valve, and OEM style seals included where applicable.

Product Features:

High grade stainless steel and copper construction
Meets or exceeds OEM standards
Consistent and precise response to cooling system needs
Original equipment design for worry-free direct fit replacement
100% tested and calibrated

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$13.99

Product Features:

Choosing Victor Reinz assures getting OE quality parts in gaskets sets that have the coverage, contents, packaging and electronic cataloging to best meet the needs of the aftermarket.
Application specific design provides an exceptional fit.
Validated for fit, form, and function.
Meets or exceeds original equipment specifications.

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$95.99

Tester adapter for the MT-300 cooling system pressure testers. Professional grade test equipment to ensure an automotive cooling system is operating at the correct pressure. Made from high quality materials to ensure durability. Designed to test automotive coolant caps.

Product Features:

Machined metal construction
Works with MT-300 pressure tester
Tests coolant caps
Professional quality

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$7.49

Meets or exceeds all original equipment specifications
Application specific design
Manufactured for the sealing repair environment
Validated for fit, form, and function
Quality that you can trust

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$39.99

ACDelco Professional Engine Coolant Temperature Sensor is a high quality aftermarket replacement component for one or more of the following vehicle systems: ignition, and/or engine fuel management. This premium aftermarket sensor is manufactured to meet or exceed your expectations for fit, form, and function.

Product Features:

Professional, premium aftermarket replacement
Provides the performance and dependability you expect from ACDelco
Manufactured to meet expectations for fit, form, and function

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$40.99

Delphi’s history is one of OE heritage and quality. Our global technical requirements include design specifications and validation testing based on over 100 years of OE experience. Our material selections, material thickness, and material types are built from OE specifications to exceed aftermarket expectations. We put in place strict manufacturing processes to ensure quality control in every part we make. Delphi’s pioneering spirit delivers innovative solutions designed to support the aftermarket in servicing the vehicles of today, and tomorrow.

Product Features:

Delphi temperature sensors deliver accurate readings and optimal performance
Delphi’s 1 piece design and automated production process eliminates internal connectors and failure points
Each sensor is electrically insulated to eliminate interference from other components in the vehicle
Delphi temperature sensors are impervious to electrical noise and interference

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$99.99

Our products are engineered and tested to provide years of trouble free operation. Backed by over 50 years of mobile a/c experience, fix it once and fix it right with Imperial.

Product Features:

Motors built and tested to quality specifications
14 in. universal fit reversible fan
1250 CFM
UNIVERSAL fan, NOT a direct OE replacement. Measure core and verify space.
Motors built and tested to quality specifications
14 in. universal fit reversible fan
1250 CFM
UNIVERSAL fan, NOT a direct OE replacement. Measure core and verify space.

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$108.99

Our products are engineered and tested to provide years of trouble free operation. Backed by over 50 years of mobile a/c experience, fix it once and fix it right with Imperial.

Product Features:

Rapid-Cool Thin-Line electric fans
12″ Diameter
800 CFM
Use as a pusher or puller fan
Motors built and tested to quality specifications
12 in. universal fit reversible fan
800 CFM
UNIVERSAL fan, NOT a direct OE replacement. Measure core and verify space.

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$99.99

All modern vehicles consist of several independent operating systems controlled by a main system processor with independent sub-processors. The sub-processors provide class 2 serial information data to the main processor while handling the operation of the system and carry the circuit load to protect the main operating system. When replacing any level processor programming may be needed to enter the unit into the vehicles main operating system.

Product Features:

Product constructed to meet all design and operating characteristics as intended by the vehicle manufacturer.

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$70.99

Adjustable Thermostatic Fan Control. 160-210°F; push-in probe. Controls the operating temperature of Imperial electric fans. Operates up to 2 fans.

Product Features:

Adjustable thermostatic fan control
160-210°F push-in probe
For use with Imperial electric fans
Probe installs into radiator fins

Popular 2003 Chevrolet Trailblazer Ext Engine Cooling Parts Categories

Radiators

Water Pumps

Engine Cooling Fan Controllers

Thermostat and Water Outlet Assemblies

Engine Coolant Air Bleed Pipes

Coolant Reservoirs

Coolant Temperature Sensors

Coolant Reservoir Caps

Water Outlets

Radiator Fan Control Relays

Water Pump Install. Kits

Engine Coolant Thermostat O-Rings

Thermostat Housing Gaskets

Thermostat Housings

Water Pump Gaskets

Coolant Fan Motor Connectors

Coolant Level Sensors

Radiator Cap Adapters

Water Pump O-Rings

Engine Water Pump with Fan Clutch

Thermostat Shims

Engine Coolant Crossover Pipe Kit

Most Popular Thermostats for 2003 Chevrolet Trailblazer Exts

Enhance your 2003 Chevrolet Trailblazer Ext with one of the 8 Thermostats we have in stock, starting at just $17.49.

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$17.99

Carquest Premium Thermostats are manufactured with OEM quality materials and safety standards by an OE Supplier. This thermostat will meet and exceed the expectations of the OE thermostat to insure the best product for your cooling system. Stands up to even the most demanding automotive cooling systems. Manufactured with OEM specifications and processes. Copper case and wax compound assures rapid response to temperature changes in the coolant. Offset design, air relief valve, and OEM style seals included where applicable.

Product Features:

High grade stainless steel and copper construction
Meets or exceeds OEM standards
Consistent and precise response to cooling system needs
Original equipment design for worry-free direct fit replacement
100% tested and calibrated

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$58.99

Kit includes thermostat, housing, and all necessary seals/gaskets to do the complete job. These individual parts are manufactured with OEM quality materials and safety standards by an OE Supplier. This thermostat and housing will meet and exceed the expectations of the OE thermostat to insure the best product for your cooling system. Stands up to even the most demanding automotive cooling systems. Manufactured with OEM specifications and processes. Copper case and wax compound assures rapid response to temperature changes in the coolant. Offset design, air relief valve, and OEM style seals included where applicable.

Product Features:

High grade stainless steel and copper construction
Meets or exceeds OEM standards
Consistent and precise response to cooling system needs
Original equipment design for worry-free direct fit replacement
100% tested and calibrated

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$28.99

UltraStat Thermostats are the toughest thermostats on the market. All heavy gauge stainless steel construction provides long-life durability, as well as complete corrosion resitance. Exclusive BLVT Valve technology minimizes thermal shock to cooling system components.

Product Features:

Heavy gauge stainless steel components offer increased reliability and long-lasting durability
Exclusive BLVT Valve Technology minimizes thermal shock to cooling system components
Stainless steel thermal element for unmatched corrosion resistance and revolutionary REAX wax mixture provides quicker reaction time
AccuSpring Design for stable temperature control and increased cabin comfort

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$37.99

Opens sooner than stock at 180 degrees
High flow design for performance applications
Includes rubber o-ring seal/gasket
Incorporates pressure relief valve

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$17.49

Manufactured with OEM quality materials and safety standards by an OE Supplier. This thermostat will meet and exceed the expectations of the OE thermostat to insure the best product for your cooling system. Stands up to even the most demanding automotive cooling systems. Manufactured with OEM specifications and processes. Copper case and wax compound assures rapid response to temperature changes in the coolant. Offset design, air relief valve, and OEM style seals included where applicable.

Product Features:

High grade stainless steel and copper construction
Meets or exceeds OEM standards
Consistent and precise response to cooling system needs
Original equipment design for worry-free direct fit replacement
100% tested and calibrated

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$41.99

This replacement engine coolant thermostat housing is engineered to match the fit and durability of the stock thermostat housing on specified vehicles. It is designed to withstand extreme temperature changes to extend service life.

Product Features:

Ideal replacement – this engine coolant thermostat housing directly replaces the original housing on specified vehicle years, makes and models
Durable construction – this part is specifically designed to withstand extreme temperature changes and resist cracking and leaking
Cost-effective and reliable – offers original manufacturer quality at lower cost than getting replacement at dealer
Industry-leading design – professionally engineered by the aftermarket leader in replacement thermostat housings

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$33.99

Ideal replacement – this engine coolant thermostat housing directly replaces the original housing on specified vehicle years, makes and models
Durable construction – this part is specifically designed to withstand extreme temperature changes and resist cracking and leaking
Cost-effective and reliable – offers original manufacturer quality at lower cost than getting replacement at dealer
Industry-leading design – professionally engineered by the aftermarket leader in replacement thermostat housings

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$68.99

Product Features:

High grade stainless steel and copper construction
Meets or exceeds OEM standards
Consistent and precise response to cooling system needs
Original equipment design for worry-free direct fit replacement
100% tested and calibrated

Best-Selling 2003 Chevrolet Trailblazer Ext Water Pumps

Upgrade your Trailblazer Ext with one of our 7 best-selling Water Pumps, earning an average 4.5 stars rating across 915 reviews.

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$151.99

100% tested for reliable performance
Durable housing features precisely machined mounting surface for proper sealing and fitment
Equipped with weep chamber or similar feature to help prevent unnecessary replacement
Included heavy-duty unitized bearings, pressed-on hubs and optimal impeller clearance for a long-lasting water pump
All gaskets or seals necessary for water pump are included
This pump is driven by the accessory belt and we recommend replacement if nearing service recommendation
This pump is driven by the timing chain; see vehicle manufacturer recommendation for replacement of timing components
This pump is driven by the timing belt; see vehicle manufacturer recommendation for replacement of timing components
Additional Notes: Includes gasket

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$104.99

This replacement engine water pump is leak and flow tested. Gaskets and seals are included where applicable.

Product Features:

This pump is used on accessory belt driven applications
Used mostly on models equipped with a fan clutch
It is highly recommended that the fan clutch be replaced with the water pump
All gaskets or seals necessary for installation are supplied with pump
Durable housing features precisely machined mounting surfaces for proper sealing

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$71.99

Built to meet or exceed OE fit, form and function
All components necessary for installation are supplied with pump
100% tested for reliable performance
Follow all enclosed instructions to maximize pump life and validate warranty
Additional Notes: Includes gasket

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$55.99

Driveworks Remanufactured Water Pumps offer a complete replacement part solution, with application coverage spanning from antique to present-day vehicles. All units are 100% tested and engineered to meet or exceed O.E.M. performance, providing you a quality product you and your vehicle can rely on.

Product Features:

100% leak tested and hub-pull tested to promote a long, trouble-free performance life
Designed and manufactured with new, high-quality unitized seals from OE suppliers to ensure long, trouble-free performance
Each unit uses the proper bearing design as specified by the OE manufacturer to meet the specific radial torque and axial load requirements of each application to promote long bearing life and trouble-free performance
Supplied with high-quality mounting gasket and other seals/gaskets as applicable per application to help complete the job
Manufactured to original casting specifications to ensure a proper fit and proper water flow for efficient cooling

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$309.99

An ACDelco Professional, premium aftermarket Engine Water Pump circulates coolant through your vehicle’s radiator and engine system to help maintain proper engine temperature and performance. The gaskets, seals, and O-rings packaged with this Professional, premium aftermarket water pump help guarantee that all necessary parts are available for trouble-free installation. ACDelco Professional Water Pumps are a high quality replacement for many vehicles on the road today. This premium aftermarket replacement engine water pump is manufactured to meet your expectations for fit, form, and function.

Product Features:

All Makes water pumps fit GM vehicles as well as a wide range of non-GM vehicles
Thoroughly tested for reliable, leak-free performance
Coated seals support seal longevity and durability
Heat-treated shaft assemblies provide superior strength and durability over non-treated assemblies
High-quality bearings are permanently sealed and lubricated for greater durability and long life
Come with premium, high-quality replacement components needed for trouble-free and accurate installation
Uniform wall sections and smooth coolant-flow cavities for efficient operation
Cast-iron or aluminum design, depending on vehicle application

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$133.99

All Makes water pumps fit GM vehicles as well as a wide range of non-GM vehicles
Thoroughly tested for reliable, leak-free performance
Coated seals support seal longevity and durability
Heat-treated shaft assemblies provide superior strength and durability over non-treated assemblies
High-quality bearings are permanently sealed and lubricated for greater durability and long life
Come with premium, high-quality replacement components needed for trouble-free and accurate installation
Uniform wall sections and smooth coolant-flow cavities for efficient operation
Cast-iron or aluminum design, depending on vehicle application

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$188.99

Manufactured to meet or exceed OEM specifications.

Product Features:

100% factory tested for leakage and dimensional precision.
Bearing noise and durability-tested.
Designed to match OE coolant flow rate and pressure.
All required hardware included for easy installation.

Top-Quality Radiators for 2003 Chevrolet Trailblazer Exts

Choose a high-quality OEM or aftermarket Radiator for Chevrolet Trailblazer Exts and enjoy top-notch performance from $209.99.

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$209.99

Our B-type tubes feature central reinforcement to provide greater tolerance to pressure. Stronger tube design means drastically reduced probability of tube failure.
Our deep extrusion header provides a stronger tube to header joint which is more resistant to the effects of vibration and thermal tube expansion, virtually eliminating tube to header leaks.
Our fin edges are folded for increased stability and heat disbursement properties.
Our included “multi-fit” attachments allow one radiator to cover multiple vehicle applications without sacrificing OE fit. This results in wider vehicle coverage with substantially less inventory.
Thermal expansion cuts allow for longer life and reduce failure rates by allowing improved core expansion and contraction during normal heat cycles.
We design and manufacture all our radiators to meet or even exceed Original Equipment specifications. We take pride in producing the most reliable replacement parts in the market.
We use longer header tabs for increased pressure resistance. This reduces the potential for tank to header leaks.

from

$341.99

Our B-type tubes feature central reinforcement to provide greater tolerance to pressure. Stronger tube design means drastically reduced probability of tube failure.
Our deep extrusion header provides a stronger tube to header joint which is more resistant to the effects of vibration and thermal tube expansion, virtually eliminating tube to header leaks.
Our fin edges are folded for increased stability and heat disbursement properties.
Our included “multi-fit” attachments allow one radiator to cover multiple vehicle applications without sacrificing OE fit. This results in wider vehicle coverage with substantially less inventory.
Thermal expansion cuts allow for longer life and reduce failure rates by allowing improved core expansion and contraction during normal heat cycles.
We design and manufacture all our radiators to meet or even exceed Original Equipment specifications. We take pride in producing the most reliable replacement parts in the market.
We use longer header tabs for increased pressure resistance. This reduces the potential for tank to header leaks.

Top Picks for 2003 Chevrolet Trailblazer Ext Water Pump Gaskets

Invest in one of our 4 durable Water Pump Gaskets for your 2003 Chevrolet, knowing you’re getting trusted brands and expert craftsmanship.

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$7.99

MAHLE® gaskets provide world class sealing products trusted by OEMs & Technicians around the globe.

Product Features:

All MAHLE gaskets meet or exceed the original equipment specifications providing the finest sealing products available
MAHLE gaskets utilizes OE equivalent or better materials in all our gaskets
MAHLE gaskets is the leader in Domestic, Asian and European applications
The contents of MAHLE gaskets are packaged in shrink wrapped tray, giving you the added security of knowing that you have the right parts, prior to opening the package

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$7.49

Fel-Pro gaskets are specifically designed for the repair environment to deliver a reliable seal on even the most troublesome applications. Designed for imperfect sealing surfaces and manufactured with proprietary materials, you can count on Fel-Pro for innovative sealing solutions for the real-world repair environment.

Product Features:

Meets or exceeds all original equipment specifications
Application specific design
Manufactured for the sealing repair environment
Validated for fit, form, and function
Quality that you can trust

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$5.79

Fel-Pro gaskets offer 100% vehicle sealing with application-specific materials to give you sealing solutions with the performance and durability professionals trust.

Product Features:

Meets or exceeds all original equipment specifications
Application specific design
Manufactured for the sealing repair environment
Validated for fit, form, and function
Quality that you can trust

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$6.99

With Victor Reinz gaskets, you can be sure you are getting sealing solutions that deliver OE quality gasket technology and engineering. That is because Victor Reinz is an original equipment supplier and the trusted choice of manufacturers the world over, offering broad coverage for foreign and domestic cars and trucks. In Victor Reinz gasket sets, you get the right combination of components needed for fast, long-lasting repairs.

Product Features:

Choosing Victor Reinz assures getting OE quality parts in gaskets sets that have the coverage, contents, packaging and electronic cataloging to best meet the needs of the aftermarket.

Top-Rated Thermostat and Water Outlet Assemblies for 2003 Chevrolet Trailblazer Exts

Make a smart move for your 2003 Chevrolet Trailblazer Ext with products all priced from $39.49 to $74.99.

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from

$39.49

High grade stainless steel and copper construction
Meets or exceeds OEM standards
Consistent and precise response to cooling system needs
Original equipment design for worry-free direct fit replacement
100% tested and calibrated

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$53.99

Ideal replacement – this engine coolant thermostat housing directly replaces the original housing on specified vehicle years, makes and models
Durable construction – this part is specifically designed to withstand extreme temperature changes and resist cracking and leaking
Cost-effective and reliable – offers original manufacturer quality at lower cost than getting replacement at dealer
Industry-leading design – professionally engineered by the aftermarket leader in replacement thermostat housings

from

$74.99

Ideal replacement – this engine coolant thermostat housing directly replaces the original housing on specified vehicle years, makes and models
Durable construction – this part is specifically designed to withstand extreme temperature changes and resist cracking and leaking
Cost-effective and reliable – offers original manufacturer quality at lower cost than getting replacement at dealer
Industry-leading design – professionally engineered by the aftermarket leader in replacement thermostat housings

from

$65.99

Ideal replacement – this engine coolant thermostat housing directly replaces the original housing on specified vehicle years, makes and models
Durable construction – this part is specifically designed to withstand extreme temperature changes and resist cracking and leaking
Cost-effective and reliable – offers original manufacturer quality at lower cost than getting replacement at dealer
Industry-leading design – professionally engineered by the aftermarket leader in replacement thermostat housings

from

$54.99

Includes quality gasket to ensure proper seal

from

$39.99

Ideal replacement – this engine coolant thermostat housing directly replaces the original housing on specified vehicle years, makes and models
Durable construction – this part is specifically designed to withstand extreme temperature changes and resist cracking and leaking
Cost-effective and reliable – offers original manufacturer quality at lower cost than getting replacement at dealer
Industry-leading design – professionally engineered by the aftermarket leader in replacement thermostat housings

Top-Rated Engine Cooling Part Brands For Your 2003 Chevrolet Trailblazer Ext

When it comes to finding the perfect Engine Cooling Part for your 2003 Chevrolet Trailblazer Ext, Advance Auto Parts has you covered with a wide selection of high-quality OEM and aftermarket options from 19 trusted brands. We carry the most popular Engine Cooling Part brands including Felpro, Carquest Premium, and Dorman, and more, all known for their exceptional customer ratings (average brand rating of 4.6 stars) and competitive prices, as low as $5.79. Purchasing a Engine Cooling Part from us here at Advance Auto Parts is a smart move for both you and your 2003 Chevrolet Trailblazer Ext, providing peace of mind with parts that meet or exceed OEM standards.

Popular Felpro 2003 Chevrolet Trailblazer Ext Engine Cooling Parts

If you’re looking for a top-quality Engine Cooling Part for your 2003 Chevrolet Trailblazer Ext, Advance Auto Parts has exactly what you need with our selection of Felpro Engine Cooling Parts. We have 3 Felpro Engine Cooling Parts in stock for this fitment, all known for their durability and precision fit. With prices starting at just $5.79 and an average cost of $6.92, you’ll find the perfect Engine Cooling Part for your needs and budget. Felpro Engine Cooling Parts for the 2003 Chevrolet Trailblazer Ext come highly rated, with over 120 customer reviews and an impressive average rating of 4.6 stars. Choosing a Felpro Engine Cooling Part from Advance Auto Parts is a smart move to ensure quality and value for your vehicle.

from $7.49

(9)

Engine Water Pump Gasket Kit

“OEM Quality, no rtv needed to make these work which makes it so much faster if you need to replace the water pump again in the future.”

from $5.79

(11)

Engine Water Pump Gasket

“Very good”

from $7.49

(100)

Engine Water Pump Gasket

“Great”

Top-Quality Carquest Premium 2003 Chevrolet Trailblazer Ext Engine Cooling Parts

For those in search of a high-quality Engine Cooling Part for their 2003 Chevrolet Trailblazer Ext, Advance Auto Parts offers a great selection of Carquest Premium Engine Cooling Parts. With 3 Carquest Premium Engine Cooling Parts in stock, you can trust you’re getting top-tier parts designed for durability and a perfect fit. Prices for these Engine Cooling Parts start at just $17.99, with an average price of $80.66, giving you a range of options to suit your budget. Backed by over 738 customer ratings and an average rating of 4.4 stars, Carquest Premium Engine Cooling Parts provide both reliability and excellent performance. Choosing a Carquest Premium Engine Cooling Part from Advance Auto Parts is a smart investment in your vehicle’s performance and longevity.

from $151.99

(371)

Engine Water Pump: New, Gasket/Seals Included

“this was one of the easys’t waterpumps i have ever installed”

from $17.99

(189)

Standard Thermostat: With Seal, 187 Degrees

“Good”

from $71.99

(178)

Engine Water Pump: New, Gasket/Seals Included

“Was exactly same as factory”

FAQs for 2003 Chevrolet Trailblazer Ext Engine Cooling Parts

What are the best-selling Engine Cooling Parts for 2003 Chevrolet Trailblazer Exts?

Out of 71 Engine Cooling Parts that fit 2003 Chevrolet Trailblazer Exts, the following parts are the top sellers:

Engine Water Pump (20420611) – $104.99
Engine Water Pump Gasket (15780035) – $7.49
Radiator Cap: 15 PSI (17110030) – $15.99

What’s the price range for 2003 Chevrolet Trailblazer Ext Engine Cooling Parts?

The prices of Engine Cooling Parts for the 2003 Chevrolet Trailblazer Ext range from $3.29 up to $341.99 for the most premium parts.

What is the average price of an Engine Cooling Part for a 2003 Chevrolet Trailblazer Ext?

The average price for Engine Cooling Parts for the 2003 Chevrolet Trailblazer Ext is $75.97. Keep in mind the variety of part types within our Engine Cooling Part category, where you are likely to find a wide range of prices across a variety of parts and components.

Does Advance Auto Parts sell Engine Cooling Parts for other Chevrolet Trailblazer Ext model years?

Yes, we carry Engine Cooling Parts for 3 model years of Chevrolet Trailblazer Exts between 2002 and 2006. The following model years are the most popular for Engine Cooling Part purchases: 2006, 2005, 2004, and 2002.

What are the cheapest Engine Cooling Parts for my 2003 Chevrolet Trailblazer Ext?

The cheapest 2003 Chevrolet Trailblazer Ext Engine Cooling Parts we carry are:

Multi-Purpose O-Ring (15780472) – $3.29
Engine Coolant Thermostat Gasket (15780471) – $4.99
Engine Water Pump Gasket (20688649) – $5.79
Engine Water Pump Gasket (12547238) – $6.99
Engine Water Pump Gasket (15780035) – $7.49

Does Advance Auto Parts sell Engine Cooling Parts for any other 2003 Chevrolet models?

Yes. We stock Engine Cooling Parts for 32 other popular 2003 Chevrolet models. Some of the most popular are 2003 Tahoe Engine Cooling Parts, 2003 Impala Engine Cooling Parts, 2003 Silverado 1500 Engine Cooling Parts, 2003 Malibu Engine Cooling Parts, and 2003 Suburban 1500 Engine Cooling Parts.

What are the top-rated Engine Cooling Parts that fit the 2003 Chevrolet Trailblazer Ext?

The one 2003 Chevrolet Trailblazer Ext Engine Cooling Part we have in stock is the Multi-Purpose O-Ring. It costs $3.29.

What types of Engine Cooling Parts do you sell for my 2003 Chevrolet Trailblazer Ext?

As of 3/1/26, these are some of the most in-demand types of Engine Cooling Parts for a 2003 Chevrolet Trailblazer Ext:

Can I get help with 2003 Chevrolet Trailblazer Ext Engine Cooling Part orders?

Contact our customer support team by chat or phone, through the help desk page, where you can find instant answers about Chevrolet Engine Cooling Parts and more.

What is your return policy for Chevrolet Trailblazer Ext Engine Cooling Parts?

Advance Auto Parts keeps returns simple. For new Chevrolet Trailblazer Ext Engine Cooling Parts and accessories, your online orders can be returned, in their original condition, within 45 days. For requirements, see the returns page.

2003 Chevrolet Trailblazer Ext Engine Cooling Parts

Dorman – Help – Engine Coolant Reservoir Cap: Twist, Plastic, 1 Pack (Part No.82594)

Carquest Premium – Engine Water Pump: New, Gasket/Seals Included (Part No.T1231)

Mr. Gasket – Thermocap Radiator Cap (Part No.2476BK)

Felpro – Multi-Purpose O-Ring (Part No.35633)

Carquest Premium – Engine Coolant Level Sensor (Part No.SBA3711)

Dorman – Radiator Fan Motor Connector (Part No.645-176)

Carquest Premium – Coolant Housing/Water Outlet (Part No.85096)

Dorman – Engine Heater Hose Assembly (Part No.626-591)

Mr. Gasket – Tstat (Part No.6368)

Mr. Gasket – Water Neck (Part No.2670)

GM Genuine Parts – Multi-Purpose Relay (Part No.15016745)

Felpro – Engine Water Pump Gasket (Part No.35704)

US MOTOR WORKS – Water Pump with Fan Clutch (Part No.MCK1008)

Carquest Premium – Radiator (Part No.432405)

Holley – LS Steam Tube Kit with Black Push-On Hose (Part No.26-552)

Felpro – Engine Coolant Thermostat Gasket (Part No.35632)

Carquest Premium – Electronic Fan Clutch – Reverse Rotation, Heavy Duty (Part No.215156)

Dorman – Non-Pressurized Coolant Reservoir: White, Plastic, Original Equipment Replacement (Part No.603-126)

Carquest Premium – Integrated Thermostat Housing: With Seal, 192 Degrees (Part No.14659)

Victor Reinz – Engine Coolant Thermostat Housing Gasket (Part No.71-14094-00)

Carquest Premium – Radiator Cap Tester Adapter (Part No.12033)

Felpro – Engine Water Pump Gasket Kit (Part No.ES 73010)

ACDelco – Engine Coolant Temperature Sensor (Part No.213-4514)

Delphi – Engine Coolant Temperature Sensor (Part No.TS10076)

Imperial – Electric Fan, 14" Diameter (Part No.226114)

Imperial – Electric Fan, 12" Diameter (Part No.226112)

Carquest Premium – Engine Cooling Fan Module (Part No.ACC1313)

Imperial – Adjustable Thermostatic Fan Control (Part No.226204)

Carquest Premium – Standard Thermostat: With Seal, 187 Degrees (Part No.14948)

Motorad – Engine Coolant Thermostat Housing Assembly Thermostat: With Inlet, With Seal, 187 Degrees (Part No.524KT)

Motorad UltraStats – Thermostat: With Seal, 187 Degrees (Part No.5456-187)

Mr. Gasket – Tstat (Part No.6368)

Motorad – Standard Thermostat: With Seal, 187 Degrees (Part No.524-190)

Dorman – Thermostat Assembly: Includes Housing, Thermostat, and O-Ring, 180 Degrees (Part No.902-2700)

Dorman – Thermostat Assembly: Includes Housing, Thermostat, and Gasket, 186 Degrees (Part No.902-700)

Carquest Premium – Integrated Thermostat Housing: With Seal, 180 Degrees (Part No.413-180)

Carquest Premium – Engine Water Pump: New, Gasket/Seals Included (Part No.T7052)

Driveworks Water Pumps – Engine Water Pump (Part No.58-562)

Carquest Premium – Engine Water Pump: New, Gasket/Seals Included (Part No.T1231)

Driveworks Water Pumps – Water Pump (Part No.58-588)

ACDelco – Water Pump Kit (Part No.252-845)

ACDelco – Water Pump Kit (Part No.252-822)

Carquest Premium – Engine Water Pump with Thermostat and Housing (Part No.T7181)

Carquest Premium – Radiator: With Transmission Oil Cooler (Part No.432403)

Carquest Premium – Radiator (Part No.432405)

MAHLE Original – Water Pump Gasket (Part No.K31757)

Felpro – Engine Water Pump Gasket (Part No.35635)

Felpro – Engine Water Pump Gasket (Part No.35704)

Victor Reinz – Engine Water Pump Gasket (Part No.71-14691-00)

Carquest Premium – Integrated Thermostat Housing: With Seal, 192 Degrees (Part No.14659)

Dorman – Thermostat Assembly: Includes Housing, Thermostat, and O-Ring, 180 Degrees (Part No.902-2131)

Dorman – Thermostat Assembly: Includes Housing (Part No.902-2836)

Dorman – Thermostat Assembly: Includes Housing and O-Ring, 160 Degrees (Part No.902-2701)

Factory Air – Water Outlet with Thermostat (Part No.85580)

Dorman – Thermostat Assembly: Includes Gasket, Thermostat, and Housing, 160 Degrees (Part No.902-2800)