2003 Chevrolet Trailblazer Ext Engine Cooling 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 Thermostat and Water Outlet Gaskets, Thermostats, and Water Pumps. 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, Dorman, and Carquest Premium. For example, FELPRO Engine Cooling Parts start at just $5.79 with an average 4.6 star rating. Dorman and Carquest Premium offer similar pricing and quality, backed by strong customer feedback. With over 5,673 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 $76.18, with a range that starts at $4.79 and goes up to $341.99. With 68 options in stock from 17 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.

Essential 2003 Chevrolet Trailblazer Ext Engine Cooling Parts

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

Engine Coolant Reservoir Cap: Twist, Plastic, 1 Pack

from

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

Engine Water Pump

from

$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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Mr. Gasket – Thermocap Radiator Cap (Part No.2471S)

Thermocap Radiator Cap

from

$51.99
Knowing your coolant temperature can help to prevent burn injuries. Thermocap Cap, with its built-in calibrated thermometer, indicates the coolant temperature. This is useful information prior to cap removal. Never attempt to remove Thermocap Cap when the coolant temperature is very hot. The escaping hot coolant and steam may burn you. Reclamation valve works great with your coolant recovery system. Your radiator can reclaim coolant from your overflow bottle. Wide 30 degree to 270 degree F temperature range. Calibrated in centigrade and Fahrenheit. Color-coded temperature ranges.

Product Features:
  • Indicates Coolant Temperature
  • Helps to Prevent Injuries from coolant or steam burns
  • Integrated Coolant Reclamation Valve
  • Improves Underhood Appearance
  • Fahrenheit and centigrade readings
  • Various valve pressures available
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Carquest Premium – Engine Coolant Level Sensor (Part No.SBA3711)

Engine Coolant Level Sensor

from

$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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Carquest Premium – Multi-Use Connector (Part No.PTA1174)

Multi-Use Connector

from

$37.99
Modern vehicles may have 100 or more electrical harness connectors in every operating system of the vehicle. Terminal tension may weaken with time or corrosion may occur within the connector housing making replacement necessary. When replacing any harness-connector assembly approved wire termination methods must be followed to ensure a successful and long-term solution to the original problem is made. A failed terminal connection, terminal corrosion or damaged wire will result in an electrical system fault.

Product Features:
  • Carquest electrical connectors meet or exceed OE wire gauge, insulation, and terminal material requirements.
  • WVE electrical connectors meet or exceed OE wire gauge, insulation, and terminal material requirements.
  • Product constructed to meet all design and operating characteristics as intended by the manufacturer.
  • OE specified wire gauge to ensure a reliable electrical connection
  • Designed to meet or exceed OE specifications in form, fit and function
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Victor Reinz – Engine Water Pump Gasket (Part No.71-14691-00)

Engine Water Pump Gasket

from

$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.
See More

Dorman – Engine Coolant Water Outlet (Part No.902-695)

Engine Coolant Water Outlet

from

$54.99
This replacement engine coolant water outlet is engineered to match the fit and durability of the stock engine coolant water outlet on specified vehicles. It is designed to withstand extreme temperature changes to extend service life.

Product Features:
  • Ideal replacement – this engine coolant water outlet directly replaces the original water outlet 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 water outlets
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Dorman – Engine Heater Hose Assembly (Part No.626-543)

Engine Heater Hose Assembly

from

$86.99
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
See More

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

Thermostat: With Seal, 187 Degrees

from

$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
See More

Carquest Premium – Engine Coolant Thermostat Housing (Part No.85254)

Engine Coolant Thermostat Housing

from

$54.99
High quality OE replacement part with all components needed to complete the job.

Product Features:
  • Meets and/or exceeds OEM standard
  • Includes quality gasket or O-ring  to ensure proper seal (where applicable)
  • Includes quality gasket or O-ringá to ensure proper seal (where applicable)
  • Coated with corrosion and rust inhibitor
  • 100% leak tested
  • Direct-fit replacement for ease of installation
  • Meets and/or exceeds OEM standard
  • Includes quality gasket or O-ring to ensure proper seal (where applicable)
  • Coated with corrosion and rust inhibitor
  • 100% leak tested
  • Direct-fit replacement for ease of installation
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Felpro – Engine Water Pump Gasket Kit (Part No.ES 73010)

Engine Water Pump Gasket Kit

from

$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
See More

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

Engine Coolant Thermostat Gasket

from

$4.79
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 to ensure a perfect fit
  • Engineered and manufactured specifically for the repair environment
  • Unsurpassed quality you can trust
  • Validated for fit, form, and function
See More

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

Radiator Cap Tester Adapter

from

$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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Carquest Premium – Radiator: With Transmission Oil Cooler (Part No.432405)

Radiator: With Transmission Oil Cooler

from

$341.99
Carquest Premium radiators are designed and engineered for maximum performance, using the highest-grade materials to ensure all radiators meet or exceed original equipment (O.E.) fit, form and function. Carquest Premium radiators are built by manufacturers that meet IATF 16949 certified framework, an internationally recognized proof of quality in the automotive industry. Most modern vehicles use radiators with plastic tanks and our parts are engineered with integrated ribbing to prevent damage during thermal cycling. Carquest Premium radiators are also 100% tested to ensure a durable, leak-free cooling system repair.

Product Features:
  • Thermal tested under real-life temperature simulations
  • High tensile strength aluminum for maximum crimp strength
  • Plastic tanks are engineeredáwith integrated ribbingáfor addedástrength to withstand cracks, bowing and distortion during thermal cycles
  • Thermal expansion slots extend core life and reduce failure rates by allowing improved core expansion and contraction during systematic heat cycles
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Dorman – Clutch Fan Blade: Plastic, Cost Effective and Reliable (Part No.620-619)

Clutch Fan Blade: Plastic, Cost Effective and Reliable

from

$134.99
Replace your damaged cooling fan blade with this direct replacement. This vehicle-specific application is engineered for a perfect fit and is made from quality materials to ensure durability and restore proper cooling system operation.

Product Features:
  • Direct replacement – this engine cooling fan blade fits and functions like the original equipment fan blade
  • Quality construction – manufactured from premium materials for a long service life
  • Excellent value – original equipment quality at a lower price
  • Quality tested – has undergone testing to ensure proper fit and performance
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US MOTOR WORKS – Water Pump with Fan Clutch (Part No.MCK2001)

Water Pump with Fan Clutch

from

$279.99
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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Dorman – Electronic Radiator Fan Clutch (Part No.622-001)

Electronic Radiator Fan Clutch

from

$278.99
This engine cooling fan clutch directly replaces the original equipment part on specified vehicles. It is engineered for durability and made of quality components to ensure proper cooling system operation when the original fan clutch has failed.

Product Features:
  • Ideal replacement – this cooling fan clutch directly replaces the original fan clutch on specified vehicle years, makes and models
  • Durable construction – this fan clutch is designed to withstand extreme temperature to ensure proper cooling system operation
  • Cost-effective solution – offers original equipment fit and function at a competitive price
  • Trustworthy quality – backed by a team of designers and engineers in the United States
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Dorman – Non-Pressurized Coolant Reservoir: White, Plastic, Original Equipment Replacement (Part No.603-126)

Non-Pressurized Coolant Reservoir: White, Plastic, Original Equipment Replacement

from

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

Thermostat Assembly: Includes Housing, Thermostat, and Gasket, 186 Degrees

from

$33.99
This replacement engine coolant thermostat housing assembly is engineered to match the fit and durability of the stock housing assembly on specified vehicles. It is designed to withstand extreme temperature changes to extend service life.

Product Features:
  • Ideal replacement – this engine coolant thermostat housing assembly directly replaces the original water outlet 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 housing assemblies
See More

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

Engine Coolant Thermostat Housing Gasket

from

$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.
See More

Carquest Premium – Multi-Use Connector (Part No.PTA1092)

Multi-Use Connector

from

$34.99
Modern vehicles may have 100 or more electrical harness connectors in every operating system of the vehicle. Terminal tension may weaken with time or corrosion may occur within the connector housing making replacement necessary. When replacing any harness-connector assembly approved wire termination methods must be followed to ensure a successful and long-term solution to the original problem is made. A failed terminal connection, terminal corrosion or damaged wire will result in an electrical system fault.

Product Features:
  • Carquest electrical connectors meet or exceed OE wire gauge, insulation, and terminal material requirements.
  • WVE electrical connectors meet or exceed OE wire gauge, insulation, and terminal material requirements.
  • Product constructed to meet all design and operating characteristics as intended by the manufacturer.
  • OE specified wire gauge to ensure a reliable electrical connection
  • Designed to meet or exceed OE specifications in form, fit and function
See More

Victor Reinz – Engine Water Pump Installation Kit (Part No.18-10020-01)

Engine Water Pump Installation Kit

from

$9.99
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.
See More

Carquest Premium – Coolant Temperature Sensor (Part No.WTC1033)

Coolant Temperature Sensor

from

$39.99
Carquest Premium coolant temperature sensors and switches are designed to perform in harsh engine environments and meet or exceed original equipment (O.E.) specifications. Built by manufacturers that meet IATF 16949 certified framework, an internationally recognized proof of quality in the automotive industry, Carquest Premium coolant temperature sensors and switches undergo extensive validation testing to ensure long-lasting performance and reliability. Carquest Premium coolant temperature sensors and switches are part of our Carquest Vehicle Solutions, which is a full line of engine management and electronics products that help control ignition, fuel delivery and emission systems. Carquest Vehicle Solutions are OE-quality parts designed, engineered and tested by world-class manufacturers to ensure a reliable and long-lasting repair.

Product Features:
  • Designed to meet or exceed OE specifications for fit, form and function
  • 100% factory resistance calibrated to ensure precision tolerances, resulting in extremely accurate temperature for optimal performance
  • OE precision matched thermistor ensuring sensors match OE output resistances across all temperature positions
  • O-rings, seals or thread sealant are included if required
  • Weather-tight connectors prevent leaks and corrosion for longer life
  • Extensive design validation testing and 100% end-of-line tested
  • Carquest Vehicle Solutions Technical Support available from ASE certified technicians: 1-866-687-5413
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Delphi – Engine Coolant Temperature Sensor (Part No.TS10076)

Engine Coolant Temperature Sensor

from

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

Electric Fan, 14" Diameter

from

$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.
See More

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

Electric Fan, 12" Diameter

from

$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.
See More

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

Adjustable Thermostatic Fan Control

from

$65.99
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
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Carquest Premium – Engine Cooling Fan Module (Part No.ACC1313)

Engine Cooling Fan Module

from

$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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Most Popular Thermostat and Water Outlet Gaskets for 2003 Chevrolet Trailblazer Exts

Enhance your 2003 Chevrolet Trailblazer Ext with one of the 2 Thermostat and Water Outlet Gaskets we have in stock, starting at just $4.79.

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

Engine Coolant Thermostat Gasket

from

$4.79
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 to ensure a perfect fit
  • Engineered and manufactured specifically for the repair environment
  • Unsurpassed quality you can trust
  • Validated for fit, form, and function
See More

Felpro – Engine Coolant Thermostat Housing Gasket (Part No.36009)

Engine Coolant Thermostat Housing Gasket

from

$6.99
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
See More

Best-Selling 2003 Chevrolet Trailblazer Ext Thermostats

Upgrade your Trailblazer Ext with one of our 4 best-selling Thermostats, earning an average 4.5 stars rating across 189 reviews.

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

Standard Thermostat: With Seal, 187 Degrees

from

$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
See More

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

Thermostat: With Seal, 187 Degrees

from

$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
See More

Mr. Gasket – Tstat (Part No.6368)

Tstat

from

$36.99
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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Motorad – Standard Thermostat: With Seal, 187 Degrees (Part No.524-190)

Standard Thermostat: With Seal, 187 Degrees

from

$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
See More

Top-Quality Water Pumps for 2003 Chevrolet Trailblazer Exts

Choose a high-quality OEM or aftermarket Water Pump for Chevrolet Trailblazer Exts and enjoy top-notch performance from $71.99.

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

Engine Water Pump: New, Gasket/Seals Included

from

$151.99
Carquest Premium water pumps are 100% new, high-quality parts that meet or exceed original equipment (O.E.) specifications. All components, including the housing, hub, bearings, gaskets and seals are designed for long-lasting service life. These water pumps are supplied with the gaskets or seals necessary for installation. Our Carquest Premium water pumps undergo stringent testing to ensure superior performance that we stand behind with an industry-leading warranty.

Product Features:
  • 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
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Driveworks Water Pumps – Engine Water Pump (Part No.58-562)

Engine Water Pump

from

$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
See More

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

Engine Water Pump: New, Gasket/Seals Included

from

$71.99
Carquest Premium drive motor inverter cooler water pumps are 100% new, high-quality parts that meet or exceed original equipment (O.E.) specifications. All components, including the housing, impeller, controller, gaskets, and seals are designed for long-lasting service life. These electric water pumps are supplied with the gaskets or seals necessary for installation. Our Carquest Premium auxiliary water pumps undergo stringent testing to ensure superior performance that we stand behind with an industry-leading warranty.

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

Water Pump Kit

from

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

Water Pump Kit

from

$133.99
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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Top Picks for 2003 Chevrolet Trailblazer Ext Radiators

Invest in one of our 2 durable Radiators for your 2003 Chevrolet, knowing you’re getting trusted brands and expert craftsmanship.

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

Radiator: With Transmission Oil Cooler

from

$209.99
Carquest Premium radiators are designed and engineered for maximum performance, using the highest-grade materials to ensure all radiators meet or exceed original equipment (O.E.) fit, form and function. Carquest Premium radiators are built by manufacturers that meet IATF 16949 certified framework, an internationally recognized proof of quality in the automotive industry. Most modern vehicles use radiators with plastic tanks and our parts are engineered with integrated ribbing to prevent damage during thermal cycling. Carquest Premium radiators are also 100% tested to ensure a durable, leak-free cooling system repair.

Product Features:
  • Thermal tested under real-life temperature simulations
  • High tensile strength aluminum for maximum crimp strength
  • Plastic tanks are engineered with integrated ribbing for added strength to withstand cracks, bowing and distortion during thermal cycles
  • Thermal expansion slots extend core life and reduce failure rates by allowing improved core expansion and contraction during systematic heat cycles
  • Oil cooler designs meet or exceed OE standards, keeping the vehicle¿s engine and transmission performing at optimal conditions
  • OEM grade, premium fittings for transmission or engine oil coolers (where applicable)
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Carquest Premium – Radiator: With Transmission Oil Cooler (Part No.432405)

Radiator: With Transmission Oil Cooler

from

$341.99
Carquest Premium radiators are designed and engineered for maximum performance, using the highest-grade materials to ensure all radiators meet or exceed original equipment (O.E.) fit, form and function. Carquest Premium radiators are built by manufacturers that meet IATF 16949 certified framework, an internationally recognized proof of quality in the automotive industry. Most modern vehicles use radiators with plastic tanks and our parts are engineered with integrated ribbing to prevent damage during thermal cycling. Carquest Premium radiators are also 100% tested to ensure a durable, leak-free cooling system repair.

Product Features:
  • Thermal tested under real-life temperature simulations
  • High tensile strength aluminum for maximum crimp strength
  • Plastic tanks are engineeredáwith integrated ribbingáfor addedástrength to withstand cracks, bowing and distortion during thermal cycles
  • Thermal expansion slots extend core life and reduce failure rates by allowing improved core expansion and contraction during systematic heat cycles
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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 $33.99 to $74.99.

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

Integrated Thermostat Housing: With Seal, 192 Degrees

from

$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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GM Genuine Parts – Engine Coolant Thermostat Water Inlet Assembly (Part No.15-10412)

Engine Coolant Thermostat Water Inlet Assembly

from

$72.99
GM Genuine Parts Engine Coolant Thermostat / Water Inlet Assemblies are designed, engineered, and tested to rigorous standards, and are backed by General Motors. These engine coolant thermostat / water inlet assemblies contain the engine thermostat and water inlet housing. The engine coolant thermostat controls the flow of coolant through the radiator; enabling the engine to reach and maintain its normal operating temperature. The water inlet housing connects the radiator hoses to the thermostat. For certain applications, the water inlet contains threaded holes or ports for sensors and switches. 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:
  • Provides a durable leak-resistant seal
  • Repairs leaking thermostat housings
  • Corrects engine overheating caused by failed thermostat
  • Some GM Genuine Parts may have formerly appeared as ACDelco GM Original Equipment (OE)
  • GM Engineers design and validate OE parts specifically for your Chevrolet, Buick, GMC, or Cadillac vehicle
  • Original equipment parts are designed to work with your GM vehicle safety systems — aftermarket replacement parts may not meet the same OE safety regulations, depending on the part type
  • GM regularly updates production and service part designs to integrate new materials and technologies
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Motorad – Engine Coolant Thermostat Housing Assembly Thermostat: With Inlet, With Seal, 187 Degrees (Part No.524KT)

Engine Coolant Thermostat Housing Assembly Thermostat: With Inlet, With Seal, 187 Degrees

from

$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
See More

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

Thermostat Assembly: Includes Housing, Thermostat, and O-Ring, 180 Degrees

from

$53.99
This replacement engine coolant thermostat housing assembly is engineered to match the fit and durability of the stock housing assembly on specified vehicles. It is designed to withstand extreme temperature changes to extend service life.

Product Features:
  • Ideal replacement – this engine coolant thermostat housing assembly directly replaces the original water outlet 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 housing assemblies
See More

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

Thermostat Assembly: Includes Housing, Thermostat, and O-Ring, 180 Degrees

from

$41.99
This replacement engine coolant thermostat housing assembly is engineered to match the fit and durability of the stock housing assembly on specified vehicles. It is designed to withstand extreme temperature changes to extend service life.

Product Features:
  • Ideal replacement – this engine coolant thermostat housing assembly directly replaces the original water outlet 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 housing assemblies
See More

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

Thermostat Assembly: Includes Housing, Thermostat, and Gasket, 186 Degrees

from

$33.99
This replacement engine coolant thermostat housing assembly is engineered to match the fit and durability of the stock housing assembly on specified vehicles. It is designed to withstand extreme temperature changes to extend service life.

Product Features:
  • Ideal replacement – this engine coolant thermostat housing assembly directly replaces the original water outlet 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 housing assemblies
See More

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

Thermostat Assembly: Includes Housing

from

$74.99
This replacement engine coolant thermostat housing assembly is engineered to match the fit and durability of the stock housing assembly on specified vehicles. It is designed to withstand extreme temperature changes to extend service life.

Product Features:
  • Ideal replacement – this engine coolant thermostat housing assembly directly replaces the original water outlet 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 housing assemblies
See More

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

Integrated Thermostat Housing: With Seal, 180 Degrees

from

$68.99
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:


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
See More

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

Thermostat Assembly: Includes Housing and O-Ring, 160 Degrees

from

$65.99
This replacement engine coolant thermostat housing assembly is engineered to match the fit and durability of the stock housing assembly on specified vehicles. It is designed to withstand extreme temperature changes to extend service life.

Product Features:
  • Ideal replacement – this engine coolant thermostat housing assembly directly replaces the original water outlet 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 housing assemblies
See More

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

Water Outlet with Thermostat

from

$54.99
Includes quality gasket to ensure proper seal
See More

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

Thermostat Assembly: Includes Gasket, Thermostat, and Housing, 160 Degrees

from

$39.99
This replacement engine coolant thermostat housing assembly is engineered to match the fit and durability of the stock housing assembly on specified vehicles. It is designed to withstand extreme temperature changes to extend service life.

Product Features:
  • Ideal replacement – this engine coolant thermostat housing assembly directly replaces the original water outlet 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 housing assemblies
See More

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 17 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.
Engine Water Pump Gasket Kit
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.”
Engine Water Pump Gasket
from $5.79
(11)
Engine Water Pump Gasket
“Very good”
Engine Water Pump Gasket
from $7.49
(100)
Engine Water Pump Gasket
“Great product …easy to use”

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.
Engine Water Pump: New, Gasket/Seals Included
from $151.99
(371)
Engine Water Pump: New, Gasket/Seals Included
“this was one of the easys’t waterpumps i have ever installed”
Standard Thermostat: With Seal, 187 Degrees
from $17.99
(189)
Standard Thermostat: With Seal, 187 Degrees
“Good”
Engine Water Pump: New, Gasket/Seals Included
from $71.99
(178)
Engine Water Pump: New, Gasket/Seals Included
“Great service & fast , thank you”

FAQs for 2003 Chevrolet Trailblazer Ext Engine Cooling Parts

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

Out of 68 Engine Cooling Parts that fit 2003 Chevrolet Trailblazer Exts, the following parts are the top sellers:

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 $4.79 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 $76.18. 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:

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?

Based on 5,673 reviews by customers, our 2003 Chevrolet Trailblazer Ext Engine Cooling Parts have an average customer rating of 4 stars. These are the highest-rated categories of Engine Cooling Parts for the 2003 Chevrolet Trailblazer Ext and their top-rated products:

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

As of 11/2/25, 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.