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Details
| Specification | Value |
|---|---|
| Brand | ORIGINAL IMPERIUM |
| Category | coolant expansion tank |
| Weight [g] | 857 g |
OE/OEM numbers (5)
Search by this OE number to find compatible parts
- AUDI / CUPRA / SEAT / SKODA / VW—4G0121403A
- AUDI / CUPRA / SEAT / SKODA / VW—4G0121403AC
- AUDI / CUPRA / SEAT / SKODA / VW—4G0121403AG
- AUDI / CUPRA / SEAT / SKODA / VW—4G0121403D
- AUDI / CUPRA / SEAT / SKODA / VW—4G0121403G
Where this part fits
Original-fit position for OE 4G0121403AC. The red ring marks where this part installs on the vehicle.
About this product
The ORIGINAL IMPERIUM coolant expansion tank (230684) is a professional-grade replacement component engineered for long service life and reliable operation across all conditions your vehicle encounters. The part is built to the following specification: Weight [g]: 857 g, Supplementary Article/Info 2: 567, Additionally required articles (article numbers): 43016. Each dimension is checked against the OEM reference to ensure the component seats and functions correctly first time. Verified to fit AUDI models. All compatibility data is cross-checked against the TecDoc database — select your vehicle to confirm the part matches your specific engine and year. This part supersedes original equipment references: 171863, 2140185, 22317, 31819 and 13 more. Matching these numbers confirms a like-for-like replacement with no loss of function. ORIGINAL IMPERIUM is a recognised supplier of automotive replacement components to independent workshops and dealer networks across Europe. All parts are sourced from authorised distribution channels and carry full manufacturer traceability — you receive exactly the same component supplied to professional garages and dealer workshops. If fitment or specifications do not match your vehicle, our technical team can help identify the correct alternative — use the vehicle selector or contact us with your VIN for a guaranteed-fit recommendation. Replacing worn components on schedule preserves your vehicle's safety, reliability, and resale value — and aftermarket parts from established brands deliver OEM-equivalent performance at a fraction of the dealer price. Every part is dispatched from our UK warehouse with a 30-day money-back guarantee and free hassle-free returns.
Suitable cars
Equivalent products (12)
coolant expansion tank ORIGINAL IMPERIUM 230684 — compatible car models
| Car models | AUDI: A6 Allroad C7 (4GH, 4GJ), A6 C7 (4G2, 4GC), A6 C7 Avant (4G5, 4GD), A7 Sportback (4GA, 4GF), A8 D4 (4H2, 4H8, 4HC, 4HL) |
|---|---|
| Engines | 3.0 TDI quattro; 1.8 TFSI; 2.0 TFSI hybrid |
| Year of manufacture | 2009-2019 |
| Manufacturer article number (MPN) | 230684 |
| OE part numbers | 4G0121403A, 4G0121403AC, 4G0121403AG, 4G0121403D, 4G0121403G |
Compatibility check
Loading vehicle data…
Please wait while we load vehicle compatibility information.Description and what's included
ORIGINAL IMPERIUM 230684 coolant expansion tank. Additionally required articles (article numbers): 43016. Supplementary Article/Info 2: 567. Weight [g]: 857 g
- 1x coolant expansion tank
Shipping, returns, warranty
Free UK delivery on orders over £99.00. Express and standard shipping available.
- Standard delivery: 2-5 business days
- Express delivery: 1-2 business days
- Free returns within 14 days
- All parts backed by manufacturer warranty
Warranty: 12-month manufacturer warranty on all parts. 14-day money-back guarantee if the part doesn't fit your vehicle.
Frequently Asked Questions
Is this coolant expansion tank compatible with my car?
This coolant expansion tank fits AUDI vehicles. Use the vehicle selector at the top of the page to check exact compatibility — enter your car's make, model, and engine for a confirmed fitment match. All fitment data is verified through TecDoc.
What specifications does this ORIGINAL IMPERIUM coolant expansion tank have?
This ORIGINAL IMPERIUM coolant expansion tank has the following specifications: Weight [g]: 857 g; Supplementary Article/Info 2: 567; Additionally required articles (article numbers): 43016. Check the full specifications table above for complete details.
What OE part numbers does this coolant expansion tank replace?
This coolant expansion tank replaces OE part numbers: 4G0121403A, 4G0121403AC, 4G0121403AG, 4G0121403D, 4G0121403G. Cross-reference these numbers with your vehicle's original part number to confirm compatibility.
How much does a coolant expansion tank cost?
This ORIGINAL IMPERIUM coolant expansion tank is available for £48.99. Coolant expansion tank prices vary depending on brand, specifications, and vehicle compatibility. ORIGINAL IMPERIUM parts offer a balance of quality and value, backed by our 14-day money-back guarantee.
How do I know when to replace my coolant expansion tank?
Regular inspection of your coolant expansion tank is recommended as part of routine vehicle maintenance. Watch for changes in performance, unusual noises, or visual signs of wear. Consult your vehicle's owner manual for manufacturer-recommended replacement intervals specific to your make and model.
What tools do I need to replace a coolant expansion tank?
Tools needed: hose clamp pliers, flat-head screwdriver, 8mm socket, coolant top-up bottle. Difficulty: Easy DIY. Safety warning: Only open the expansion tank cap when the engine is completely cold -- coolant system is under pressure when hot and will spray scalding fluid if opened.
Can I use this part as a replacement for OE 4G0121403A?
Yes, this ORIGINAL IMPERIUM coolant expansion tank is a direct replacement for OE part number 4G0121403A. It is manufactured to meet or exceed original equipment specifications, ensuring proper fitment and performance. All cross-reference data is verified through TecDoc.
Related categories
Common OE numbers for this part
Common original equipment numbers linked to stocked alternatives.
