Dorman 603-861 Coolant Reservoir

In stock
SKU: 591|603861
Confirm Fitment Before You Buy
Not sure it fits? Message Year/Make/Model/Engine (2WD/4WD if applicable) and we’ll help confirm compatibility.
Why buy from Koskowski Automotive?
• 50+ years (since 1972) • Dorman Authorized Seller • Fast shipping • Easy returns
Regular price $46.87
Vehicle Fitment: Use the table below to match your exact configuration. If you don’t see your exact setup, message us before ordering.

Product details

  • SKU 591|603861
  • Barcode 889245940193

Product Description

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.

  • 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

Detailed Applications

Year Make Model Configuration Positions Application Notes
2025 Buick Envision L4 122 2.0L (1998cc)
2025 Cadillac XT4 L4 122 2.0L (1998cc)
2025 Cadillac XT5 L4 122 2.0L (1998cc)
2025 Cadillac XT5 V6 222 3.6L
2025 Cadillac XT6 L4 122 2.0L (1998cc)
2025 Cadillac XT6 V6 222 3.6L
2025 Chevrolet Blazer L4 122 2.0L (1998cc)
2025 Chevrolet Blazer V6 222 3.6L
2025 Chevrolet Colorado L4 166 2.7L (2720cc)
2025 Chevrolet Equinox L4 91 1.5L (1490cc)
2025 Chevrolet Malibu L4 91 1.5L (1490cc)
2025 GMC Canyon L4 166 2.7L (2720cc)
2025 GMC Terrain L4 91 1.5L (1490cc)
2024 Buick Envision L4 122 2.0L (1998cc)
2024 Cadillac XT4 L4 122 2.0L (1998cc)
2024 Cadillac XT5 L4 122 2.0L (1998cc)
2024 Cadillac XT5 V6 222 3.6L
2024 Cadillac XT6 L4 122 2.0L (1998cc)
2024 Cadillac XT6 V6 222 3.6L
2024 Chevrolet Blazer L4 122 2.0L (1998cc)
2024 Chevrolet Blazer V6 222 3.6L
2024 Chevrolet Colorado L4 166 2.7L (2720cc)
2024 Chevrolet Equinox L4 91 1.5L (1490cc)
2024 Chevrolet Malibu L4 91 1.5L (1490cc)
2024 GMC Canyon L4 166 2.7L (2720cc)
2024 GMC Terrain L4 91 1.5L (1490cc)
2023 Buick Envision L4 122 2.0L (1998cc)
2023 Cadillac XT4 L4 122 2.0L (1998cc)
2023 Cadillac XT5 L4 122 2.0L (1998cc)
2023 Cadillac XT5 V6 222 3.6L
2023 Cadillac XT6 L4 122 2.0L (1998cc)
2023 Cadillac XT6 V6 222 3.6L
2023 Chevrolet Blazer L4 122 2.0L (1998cc)
2023 Chevrolet Blazer V6 222 3.6L
2023 Chevrolet Colorado L4 166 2.7L (2720cc)
2023 Chevrolet Equinox L4 91 1.5L (1490cc)
2023 Chevrolet Malibu L4 91 1.5L (1490cc)
2023 GMC Acadia L4 122 2.0L (1998cc)
2023 GMC Acadia V6 222 3.6L
2023 GMC Canyon L4 166 2.7L (2720cc)
2023 GMC Terrain L4 91 1.5L (1490cc)
2022 Buick Envision L4 122 2.0L (1998cc)
2022 Cadillac XT4 L4 122 2.0L (1998cc)
2022 Cadillac XT5 L4 122 2.0L (1998cc)
2022 Cadillac XT5 V6 222 3.6L
2022 Cadillac XT6 L4 122 2.0L (1998cc)
2022 Cadillac XT6 V6 222 3.6L
2022 Chevrolet Blazer L4 122 2.0L (1998cc)
2022 Chevrolet Blazer V6 222 3.6L
2022 Chevrolet Equinox L4 91 1.5L (1490cc)
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Product Specifications

Cap Included: Yes
Cap Maximum Pressure Rating: 20 PSI
Cap Type: Threaded
Capacity: 1.5 L
Color: White
Height: 7 in
Length: 7 in
Level Sensor Included: No
Material: Plastic
Maximum Capacity: 1.5 L
Mounting Brackets Included: No
Mounting Hardware Included: No
Mounting Hole Quantity: 3
Package Contents: 1 Reservoir; 1 Cap
Package Quantity: 1
Packaging Type: Box
Pressurized: Yes
Shape: Spherical
Working Capacity: 1.5 L

OE Numbers

DIRECT OE CROSS
23386455 GENERAL MOTORS