URO 8E0121321 Engine Coolant Reservoir Cap

Name: URO 8E0121321 Engine Coolant Reservoir Cap
Brand: URO
SKU: DDWC-8E0121321
Price: 16.40 USD
Availability: InStock

57 vehicles fit this part

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OE Direct Replacement — Bolt-on fit, no modifications needed

Fitment: Audi, A4, A4 Quattro, A6, A6 Quattro, A8 Quattro, S4, S6, and S8

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Not what you need? See all Engine Coolant Reservoir Cap options

Engine Coolant Reservoir Cap for Audi

This URO engine coolant reservoir cap is built for Audi cooling systems that need a precise OE-style replacement. It is made to match original cap dimensions for reliable fitment on compatible coolant recovery tanks, including Audi A4, A4 Quattro, A6, A6 Quattro, A8 Quattro, S4, S6, and S8 applications.

Precision-molded to OE cap dimensions for proper compatibility
Quality cap and seal materials resist engine heat and cooling system exposure
Factory pressure-tested for consistent performance
Guaranteed fitment for listed applications
24 Month Unlimited Mileage Warranty

Detailed Fitment and Function

Part number 8E0121321 is an engine coolant reservoir cap designed for original and aftermarket coolant recovery tanks used on select Audi models. It helps maintain the cooling system’s sealed pressure environment, which is important for stable coolant operation in daily driving and under higher engine temperatures. This part cross-references Dorman OE Solutions 603-098 for the same application.

Compatible With 2006-2011 Audi A6, N/A; 2002-2004 Audi A6, N/A; 2000-2011 Audi A6 Quattro, N/A; 2007-2011 Audi S6, N/A; 2004-2010 Audi A8 Quattro, N/A; 2007-2009 Audi S8, N/A; 2006 Audi A4, N/A; 2002-2004 Audi A4, N/A; 2006 Audi A4 Quattro, N/A; 2002-2004 Audi A4 Quattro, N/A; 2004-2006 Audi S4, N/A; 2000-2002 Audi S4, N/A; 2005 Audi A4, N/A, Chassis Range: To 400 000; 2005 Audi A4 Quattro, N/A, Chassis Range: To 400 000; 2005 Audi S4, N/A, Chassis Range: To 400 000; 2003 Audi A8 Quattro, N/A, Chassis Range: From 4E-3-000001.

Common Uses

Replacing a cracked, worn, or leaking coolant reservoir cap
Restoring proper pressure retention in the cooling system
Addressing coolant loss caused by a cap that no longer seals correctly
Correcting warning signs tied to unstable coolant expansion tank pressure
Servicing Audi cooling system maintenance on listed A4, A6, A8, S4, S6, and S8 models

Installation Notes and Quality Assurance

Verify the reservoir style and OE part number before installation, especially on chassis-range-specific vehicles. Inspect the tank neck and seal surface for damage, then install the cap on a cool engine and confirm proper seating. URO pressure-tests this cap at the factory, and it is backed by a 24 Month Unlimited Mileage Warranty. Part number 8E0121321 is also referenced by URO and VAICO listings for the same application.

This part fits 57 vehicles. Search below:

Year	Make	Model	Submodel	Body Type	Liters	Cylinders	Position	Notes
2011	Audi	A6					N/A
2011	Audi	A6 Quattro					N/A
2011	Audi	S6					N/A
2010	Audi	A6					N/A
2010	Audi	A6 Quattro					N/A
2010	Audi	A8 Quattro					N/A
2010	Audi	S6					N/A
2009	Audi	A6					N/A
2009	Audi	A6 Quattro					N/A
2009	Audi	A8 Quattro					N/A
2009	Audi	S6					N/A
2009	Audi	S8					N/A
2008	Audi	A6					N/A
2008	Audi	A6 Quattro					N/A
2008	Audi	A8 Quattro			4.2L	V8	N/A
2008	Audi	S6					N/A
2008	Audi	S8					N/A
2007	Audi	A6					N/A
2007	Audi	A6 Quattro					N/A
2007	Audi	A8 Quattro					N/A
2007	Audi	S6					N/A
2007	Audi	S8					N/A
2006	Audi	A4			1.8L	L4	N/A
2006	Audi	A4 Quattro	Cabriolet				N/A
2006	Audi	A6					N/A
2006	Audi	A6 Quattro					N/A
2006	Audi	A8 Quattro					N/A
2006	Audi	S4	Cabriolet				N/A
2005	Audi	A4					N/A	Chassis Range: To 400 000
2005	Audi	A4 Quattro					N/A	Chassis Range: To 400 000
2005	Audi	A6 Quattro					N/A
2005	Audi	A8 Quattro					N/A
2005	Audi	S4		Convertible			N/A
2005	Audi	S4		Sedan			N/A	Chassis Range: To 400 000
2005	Audi	S4		Wagon			N/A	Chassis Range: To 400 000
2004	Audi	A4					N/A
2004	Audi	A4 Quattro					N/A
2004	Audi	A6					N/A
2004	Audi	A6 Quattro			3.0L	V6	N/A
2004	Audi	A6 Quattro			2.7L	V6	N/A
2004	Audi	A8 Quattro					N/A
2004	Audi	S4					N/A
2003	Audi	A4					N/A
2003	Audi	A4 Quattro					N/A
2003	Audi	A6					N/A
2003	Audi	A6 Quattro			3.0L	V6	N/A
2003	Audi	A6 Quattro			2.7L	V6	N/A
2003	Audi	A8 Quattro					N/A	Chassis Range: From 4E-3-000001
2002	Audi	A4					N/A
2002	Audi	A4 Quattro					N/A
2002	Audi	A6					N/A
2002	Audi	A6 Quattro			3.0L	V6	N/A
2002	Audi	S4					N/A
2001	Audi	A6 Quattro	Base		2.7L	V6	N/A
2001	Audi	S4					N/A
2000	Audi	A6 Quattro	Base		2.7L	V6	N/A
2000	Audi	S4					N/A

* Always verify fitment with your vehicle's VIN if unsure. Submodel & trim restrictions may apply.

This part directly replaces or is cross-referenced with the following part numbers:

1002380002603-0988E0 121 3218E0121321URO-008069V10-0491

Cross-reference numbers are provided for identification purposes only. Always confirm fitment before ordering.