This page lists 11 cooling system parts for the 2026 Audi A8, across 7 part types, covering both the 3.0L V6 Turbocharged and the 4.0L V8 Turbocharged. Every part shows its brand, manufacturer part number and fitment notes.
On the 2026 Audi A8, the cooling system system keeps operating temperature in the narrow band the engine was designed for, from radiator and water pump to thermostat and hoses. 7 parts of the 11 listed are Water Pump (4 parts), Coolant Reservoir Cap (2 parts) and Coolant / Antifreeze (1 part). The other 4 part types cover the remaining 4 parts.
The 2026 Audi A8 was sold with both the 3.0L V6 Turbocharged and the 4.0L V8 Turbocharged. 2 parts fit every engine; the other 9 are engine-specific. Each part shows which engine(s) it fits.
The most listed brands for 2026 Audi A8 cooling system parts are REIN (5 parts), VALVOLINE (1 part) and CALORSTAT (1 part), plus 4 more brands.
Each part number listed for the 2026 Audi A8 opens a page with every vehicle that part fits.
Coolant / Antifreeze
| Brand | Part Number | Markets | Notes | Buy |
|---|---|---|---|---|
| VALVOLINE Fits: 3.0L V6 Turbocharged | 904683 | 🇺🇸 US 🇨🇦 CA 🇲🇽 MX | HT-12 Pink1 Gallon | View on Amazon |
This table covers the engine coolants and antifreeze formulations specified for this cooling system. Typical signs include a rising temperature gauge, rusty or sludged coolant, or a heater that blows cold. Use the chemistry named in the notes. Mixing silicate, OAT and HOAT formulas can gel in the radiator.
This group shows a single part: VALVOLINE 904683.
Coolant Reservoir
| Brand | Part Number | Markets | Notes | Buy |
|---|---|---|---|---|
| REIN Fits: 3.0L V6 Turbocharged | EPT0275 | 🇺🇸 US 🇨🇦 CA 🇲🇽 MX | View on Amazon |
This table covers the overflow / expansion tanks that hold extra coolant.
One part is listed for the 2026 Audi A8 — REIN EPT0275.
Coolant Reservoir Cap
| Brand | Part Number | Markets | Notes | Buy |
|---|---|---|---|---|
| CALORSTAT Fits: 3.0L V6 Turbocharged | RC0162 | 🇺🇸 US 🇨🇦 CA 🇲🇽 MX | Maximum Pressure Rating: 23.0 PS | View on Amazon |
| MOTORAD Fits: 3.0L V6 Turbocharged | T111 | 🇺🇸 US 🇨🇦 CA 🇲🇽 MX | Standard | View on Amazon |
This table covers the caps on the overflow / expansion tank. Typical signs include a leak at the neck, a cap that will not hold pressure, or a missing tether. Match the pressure rating or thread in the notes — radiator, reservoir and fuel caps are not interchangeable.
2 Coolant Reservoir Cap parts are listed for the 2026 Audi A8, from CALORSTAT and MOTORAD.
This group includes CALORSTAT RC0162 and MOTORAD T111.
Radiator Insulator Sleeve
| Brand | Part Number | Markets | Notes | Buy |
|---|---|---|---|---|
| REIN Fits: all 2026 A8 engines | AVM0730 | 🇺🇸 US 🇨🇦 CA 🇲🇽 MX | View on Amazon |
This table covers the Radiator Insulator sleeves.
One part is listed for the 2026 Audi A8 — REIN AVM0730.
Radiator Mount
| Brand | Part Number | Markets | Notes | Buy |
|---|---|---|---|---|
| REIN Fits: all 2026 A8 engines | AVM0729 | 🇺🇸 US 🇨🇦 CA 🇲🇽 MX | Upper | View on Amazon |
This table covers the Radiator mounts. Typical signs include a clunk on takeoff, a vibration at idle, or a separated rubber insert. Support the powertrain before unbolting a mount, and torque the fasteners in the notes.
One part is listed for the 2026 Audi A8 — REIN AVM0729.
Temperature Sender / Sensor
| Brand | Part Number | Markets | Notes | Buy |
|---|---|---|---|---|
| HOLSTEIN Fits: 3.0L V6 Turbocharged | 2CTS0163 | 🇺🇸 US 🇨🇦 CA 🇲🇽 MX | Lower | View on Amazon |
This table covers the senders that report coolant temperature to the gauge or ECU. Typical signs include a gauge that sits on empty or overheat, or a lamp that does not match what the engine is doing. Rule out the cluster and the wiring before replacing the sender.
This group shows a single part: HOLSTEIN 2CTS0163.
Water Pump
| Brand | Part Number | Markets | Notes | Buy |
|---|---|---|---|---|
| HELLA Fits: 3.0L V6 Turbocharged | 358304701 | 🇺🇸 US 🇨🇦 CA | Engine CoolingAuxiliary | View on Amazon |
| REIN Fits: 3.0L V6 Turbocharged | WPA0541 | 🇺🇸 US 🇨🇦 CA 🇲🇽 MX | To TurbochargerAuxiliary | View on Amazon |
| REIN Fits: 3.0L V6 Turbocharged | WPA0555 | 🇺🇸 US 🇨🇦 CA 🇲🇽 MX | HeaterAuxiliary | View on Amazon |
| US MOTOR WORKS Fits: 3.0L V6 Turbocharged | US8214 | 🇺🇸 US 🇨🇦 CA | View on Amazon |
This table covers the pumps that circulate coolant through the block and radiator. Typical signs include coolant at the weep hole, pulley play, or a growl from the front of the engine. Replace the thermostat and refill with the specified coolant whenever the pump comes off.
4 Water Pump parts are listed for the 2026 Audi A8, from REIN, HELLA and US MOTOR WORKS.
This group includes HELLA 358304701, REIN WPA0541 and REIN WPA0555 and the remaining parts above.
Buying Cooling System Parts for a 2026 Audi A8
On this vehicle, the cooling system system keeps operating temperature in the narrow band the engine was designed for, from radiator and water pump to thermostat and hoses.
- Match the engine first. Some cooling system parts fit every engine; others are engine-specific. Each row shows which engine(s) it fits.
- Read the notes on each row for position, trim and spec qualifiers before you order.
- Where labor overlaps, replace the thermostat and refill with fresh coolant whenever you change a water pump or radiator; original hoses on an older vehicle are on borrowed time.
- Cross-reference the manufacturer part number against your old part or a service-manual listing.
Start with the largest groups on this page: Water Pump and Coolant Reservoir Cap .
Frequently Asked Questions
How many cooling system parts fit the 2026 Audi A8?
Our catalog currently lists 11 cooling system parts for the 2026 Audi A8 across 7 subcategories and 7 brands, covering both the 3.0L V6 Turbocharged and the 4.0L V8 Turbocharged. Each part is matched to the engine(s) it fits.
Do cooling system parts differ between 2026 Audi A8 engines?
Some do. 2 parts fit every engine; the other 9 are engine-specific. Each row (and the filter at the top) shows which. If you're unsure which engine you have, check the emissions label under the hood or the 8th character of your VIN.
What are the signs of cooling system problems on a 2026 Audi A8?
Common symptoms include a rising temperature gauge in traffic, sweet-smelling steam, crusty deposits around hose clamps, or a heater that blows cold. If you notice any of these, identify the affected subcategory above and cross-reference the part numbers listed.
What should I replace at the same time?
Where labor overlaps, replace the thermostat and refill with fresh coolant whenever you change a water pump or radiator; original hoses on an older vehicle are on borrowed time.
What do the market flags (US, CA, MX) on each part mean?
They show the market for which the manufacturer published application data for that part — where the vehicle was first sold, not where the part was made. If your 2026 Audi A8 was originally sold in the US, the safest choice is a part marked for the US market.
How do I make sure a part fits my 2026 Audi A8?
First match the engine — each row shows which engine(s) the part fits. Then replace coolant with the exact specification the manufacturer calls for — mixing chemistries can gel and block small passages. The notes column carries position and trim qualifiers where they apply.
Other Parts for the 2026 Audi A8
Cooling System Parts for Other Audi A8 Years
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Manufacturer names, model designations and part numbers are used for identification and fitment reference only. AutoFactsDB is an independent catalog and is not affiliated with, endorsed by, or sponsored by any vehicle manufacturer displayed on this page.