URO 8D0121403L Engine Coolant Reservoir

Brand URO 8D0121403L
Fits Audi and Volkswagen · 34 vehicles

OE dimensions. Precision-molded for compatibility with original sensors and connections.

Heat-resistant materials. Built to handle engine heat and harsh cooling system conditions.

Factory pressure-tested. Verified for dependable cooling system performance.

Cross-references Dorman - OE Solutions 603-703, Febi-Bilstein 21842 and Genuine 8D0121403L for the same application. See all 12.

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Engine Coolant Reservoir for Audi and Volkswagen

This URO engine coolant reservoir is built for direct replacement on select Audi and Volkswagen applications. It is precision-molded to OE dimensions for proper sensor and hose connection fitment, with materials selected to handle engine heat and the demands of the cooling system.

  • Direct-fit engine coolant reservoir for OE-style replacement
  • Precision-molded to original dimensions for sensor and connection compatibility
  • Heat-resistant construction for cooling system service
  • Factory pressure-tested for leak verification
  • Part number: 8D0121403L

Fitment Details

  • Fits 1998-2005 Volkswagen Passat, N/A; level sensor included
  • Fits 2003 Audi RS6, N/A; level sensor included
  • Fits 2002 Audi A4, N/A; level sensor included; chassis range through 8D-2-010000
  • Fits 2002 Audi A4 Quattro, N/A; level sensor included; chassis range through 8D-2-010000
  • Fits 1999-2001 Audi A4, N/A; level sensor included
  • Fits 1999-2001 Audi A4 Quattro, N/A; level sensor included
  • Fits 1999-2001 Audi A6, N/A; level sensor included
  • Fits 1999-2001 Audi A6 Quattro, N/A; level sensor included
  • Fits 1998 Audi A4, N/A; level sensor included; chassis range from 8D-W-007800
  • Fits 1998 Audi A4 Quattro, N/A; level sensor included; chassis range from 8D-W-007800
  • Fits 1998 Audi A6, N/A; level sensor included; chassis range from 4B-W-000001
  • Fits 1998 Audi A6 Quattro, N/A; level sensor included; chassis range from 4B-W-000001

Common Replacement Uses

  • Cracked or brittle coolant reservoir housing
  • Coolant leaks from the expansion tank
  • Faulty level sensor connection points
  • Heat-related plastic deterioration in the cooling system
  • Replacement after warning light or low-coolant condition

Installation Notes

Verify chassis range and sensor configuration before installation. Inspect the cap, hoses, and adjacent cooling system components for wear or contamination during replacement. This part cross-references Dorman OE Solutions 603-703 and VAICO V10-0556 for the same application.

Quality Assurance

URO backs this coolant reservoir with a 24 Month Unlimited Mileage Warranty. The reservoir is factory pressure-tested and made to OE dimensions to support proper fitment on Audi A4, Audi A4 Quattro, Audi A6, Audi A6 Quattro, Audi RS6, and Volkswagen Passat applications.

This part fits 34 vehicles
Always verify fitment with your vehicle's VIN if unsure. Submodel & trim restrictions may apply.
YearMakeModelSubmodelLitersCylindersPositionNotes
2005VolkswagenPassatN/ALevel sensor included
2004VolkswagenPassat2.0LL4N/ALevel sensor included
2004VolkswagenPassat2.8LV6N/ALevel sensor included
2004VolkswagenPassat1.8LL4N/ALevel sensor included
2003AudiRS6N/ALevel sensor included
2003VolkswagenPassat2.8LV6N/ALevel sensor included
2003VolkswagenPassat1.8LL4N/ALevel sensor included
2002AudiA41.8LL4N/ALevel sensor included; Chassis Range: Through 8D-2-010000
2002AudiA4 Quattro1.8LL4N/ALevel sensor included; Chassis Range: Through 8D-2-010000
2002VolkswagenPassat2.8LV6N/ALevel sensor included
2002VolkswagenPassat1.8LL4N/ALevel sensor included
2001AudiA4N/ALevel sensor included
2001AudiA4 QuattroN/ALevel sensor included
2001AudiA6N/ALevel sensor included
2001AudiA6 QuattroAvantN/ALevel sensor included
2001AudiA6 QuattroBase2.8LV6N/ALevel sensor included
2001VolkswagenPassatN/ALevel sensor included
2000AudiA4N/ALevel sensor included
2000AudiA4 QuattroN/ALevel sensor included
2000AudiA6N/ALevel sensor included
2000AudiA6 QuattroAvantN/ALevel sensor included
2000AudiA6 QuattroBase2.8LV6N/ALevel sensor included
2000VolkswagenPassatN/ALevel sensor included
1999AudiA4N/ALevel sensor included
1999AudiA4 QuattroN/ALevel sensor included
1999AudiA6N/ALevel sensor included
1999AudiA6 QuattroN/ALevel sensor included
1999VolkswagenPassatN/ALevel sensor included
1998AudiA4N/ALevel sensor included; Chassis Range: From 8D-W-007800
1998AudiA4 QuattroN/ALevel sensor included; Chassis Range: From 8D-W-007800
1998AudiA6N/ALevel sensor included; Chassis Range: From # 4B-W-000001
1998AudiA6N/ALevel sensor included; Chassis Range: From 4B-W-000001
1998AudiA6 QuattroN/ALevel sensor included; Chassis Range: From 4B-W-000001
1998VolkswagenPassatN/ALevel sensor included
Directly replaces or cross-references 12 part numbers
Cross-reference numbers are provided for identification purposes only. Always confirm fitment before ordering.
Dorman - OE Solutions — 603-703Febi-Bilstein — 21842Genuine — 8D0121403LVAICO — V10-05568D0121403LMY118 54033 001118 54033 036118 54033 280118 54033 500376755031FRT1101CURO-011478