URO 8K0121403Q Engine Coolant Reservoir

Engine Coolant Reservoir for Audi and Porsche

This URO engine coolant reservoir is a direct-fit replacement for select Audi A4, A4 Quattro, A5, A5 Quattro, allroad, Q5, and Porsche Macan applications. Built to OE dimensions and factory-tested for pressure retention, it is made for vehicles that need a precise cooling system tank replacement.

• Gray coolant reservoir with no cap included
• Precision-molded to match OE dimensions and sensor/connection locations
• Constructed from materials suited for engine heat and cooling system exposure
• Factory pressure-tested for fit and sealing verification
• Backed by a 24 Month Unlimited Mileage Warranty

Fitment Details

• Fits 2017-2018 Porsche Macan, N/A
• Fits 2013-2016 Audi A4, N/A
• Fits 2009-2011 Audi A4, N/A
• Fits 2013-2016 Audi A4 Quattro, N/A
• Fits 2010-2011 Audi A4 Quattro, N/A
• Fits 2012-2016 Audi A5 Quattro, N/A
• Fits 2013-2016 Audi allroad, N/A
• Fits 2011-2016 Audi Q5, N/A
• Fits 2012-2014 Audi A5, N/A
• Fits 2012 Audi A4, N/A, From 01/09/2012.
• Fits 2012 Audi A4 Quattro, N/A, From 01/09/2012.

Detailed Description

Part number 8K0121403Q is an OE-style coolant expansion tank for vehicles that use a gray reservoir with original sensor and hose connection points. The molded shape supports proper routing and mounting in the engine bay, making it a practical replacement for cracked, leaking, or heat-aged tanks on Audi A4 and Audi A4 Quattro models, as well as related Audi A5, A5 Quattro, allroad, Q5, and Porsche Macan applications. This part number 8K0121403Q also cross-references VAICO V10-4478 for the same application.

Common Replacement Reasons

• Coolant loss from a cracked or split reservoir
• Visible staining, warping, or heat damage on the tank
• Low coolant warnings caused by reservoir leakage
• Broken mounting points or connection issues at the tank
• Need for a direct replacement during cooling system service

Installation Notes and Tips

Verify the reservoir shape, sensor connection points, and hose routing against the original tank before installation. Transfer and inspect any reusable sensors or fittings as needed, and confirm the cooling system is properly filled and bled after replacement. For best results, inspect adjacent hoses, clamps, and the pressure cap condition during service; this reservoir is supplied without a cap.

Quality Assurance

URO manufactures this coolant reservoir to OE dimensions and pressure-tests it at the factory for fit and sealing consistency. The part number 8K0121403Q is covered by a 24 Month Unlimited Mileage Warranty.