Koyorad A13903 Radiator
OE Quality 60-Day Returns
Koyorad
 Koyorad Radiator

Koyorad A13903 Radiator

Brand Koyorad A13903
Core Height 615
Core Thickness 25
Core Width 604.8
Tank Lower/Right Length 24 1/16
Tank Lower/Right Pipe 1 1/2
Tank Lower/Right Width 1 7/8
Tank Upper/Left Height 24.1875
Tank Upper/Left Thickness 1
Tank Upper/Left Width 23.8125
Title Koyorad a13903 radiator
Product line Koyorad Radiator
Fits BMW · 3 vehicles

OE equivalent replacement. Built for original-style cooling system service and fit.

OE-style dimensions. Core and tank measurements support proper radiator packaging.

Koyorad engineering. Backed by technical know-how and replacement manufacturing experience.

Cross-references Dorman - HELP 13903 and 17119797807 for the same application. See all 2.

$200.66Free shipping
In stock · usually ships same day before 1pm CST
Step 1 — Confirm fitment
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Step 2 — Quantity
Order total $200.66
Free shipping to the continental U.S.
Free returns within 60 days if it doesn't fit when fitment is verified.
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OE Equivalent Radiator Replacement

The Koyorad A13903 radiator is an OE equivalent replacement built for direct cooling-system service. It is engineered to match the original-style fit and core dimensions needed for a proper radiator replacement on select BMW applications.

  • OE equivalent radiator from Koyorad
  • Core dimensions: 615 mm height, 604.8 mm width, and 25 mm thickness
  • Upper and lower tank measurements support original-style cooling system packaging
  • Fits 2018-2019 BMW X3 and 2019 BMW X4

Detailed Fitment and Design

Use the Koyorad A13903 when replacing a worn or leaking radiator on a BMW X3 or BMW X4 with the listed fitment. The radiator core and tank dimensions are specified to align with OE-style cooling system layout, helping maintain proper space, hose connection, and thermal management requirements. This part cross-references Dorman - HELP 13903 for the same application.

Common Replacement Reasons

  • Coolant leaks from a damaged radiator core or tank
  • Overheating caused by restricted coolant flow
  • Corrosion or age-related deterioration in the cooling system
  • Physical damage from road debris or impact

Installation Notes

Verify radiator dimensions, hose connections, and mounting points against the original unit before installation. Drain and refill the cooling system with the correct coolant specification, then bleed air from the system according to factory service procedures. Confirm fan operation and inspect for leaks after installation.

Quality Assurance

Koyorad states that its radiators are OE equivalent replacements backed by the company’s technical manufacturing experience. Part number A13903 is built for direct replacement service on the listed BMW applications.

Related reading

This part fits 3 vehicles
Always verify fitment with your vehicle's VIN if unsure. Submodel & trim restrictions may apply.
YearMakeModelTransmissionNotes
2019BMWX3AutomaticKoyorad Radiator
2019BMWX4AutomaticKoyorad Radiator
2018BMWX3AutomaticKoyorad Radiator
Directly replaces or cross-references 2 part numbers
Cross-reference numbers are provided for identification purposes only. Always confirm fitment before ordering.
Dorman - HELP — 1390317119797807