Engine: common problems, timing drive and oil

4.0 TFSI V8 twin-turbo (Audi / Porsche / Bentley)

Petrol · 3,993 / 3,996 cm³ · 309–478 kW

model generations

known faults

Enter your VIN and mileage and get a plan built for your exact engine and gearbox.

Fuel: Petrol. Timing drive: chain.

In our database this engine is fitted to 4 model generations, among them: Audi A6 (C7), Audi A7 (4G), Audi Q8 (4M), Audi A8 (D4).

The most expensive known risk is turbo oil strainer clogging → turbo failure (4.0 TFSI, to 2016): it usually appears at 80,000–180,000 km and costs €1,500–8,000 to fix.

Key facts

Fuel	Petrol
Displacement	3,993 / 3,996 cm³
Power	309–478 kW
Years	2012–2027
Timing drive	Chain
Oil	0W-30 / 5W-30 · VW 502.00 / 504.00 · ~8.3–9.5 L · every 15,000 km

Known engine faults

Faults that belong to the engine itself. They apply to every model with this engine, and each model has its own extra faults on its model page.

Turbo oil strainer clogging → turbo failure (4.0 TFSI, to 2016)

usually 80,000–180,000 km · High risk

model years 2012–2016 only

Signs: Loss of power, blue smoke, whine from the turbos

Fix: Replace the oil strainer and feed lines preventively; replace the turbos if they are damaged

€1,500–8,000

Oil separator (PCV) failure

usually 80,000–160,000 km · Medium risk

Signs: Whistling, rough idle, rising oil consumption

Fix: Replace the oil separator

€300–800

Engine-related service

Intervals and typical prices, using the Audi A6 (C7) as an example. The app gives the exact plan for your car.

Item	Interval	Typical price
Engine oil + oil filterEngine	every 15,000 km or every 12 months	€70–150
Air filterEngine	every 30,000 km or every 24 months	€15–45
Spark plugsIgnition	every 60,000 km or every 48 months	€50–160
Auxiliary (serpentine) beltEngine	every 120,000 km	€70–180
Coolant replacementCooling	every 150,000 km or every 96 months	€70–150
Timing chain inspection (listen on cold start)Engine	every 150,000 km	€0–120

Models with this engine

Model generations this engine is fitted to.

Audi A6 (C7) 2011–2018 Audi A7 (4G) 2010–2018 Audi A8 (D4) 2010–2017 Audi Q8 (4M) 2018–

Common questions

Does the 4.0 TFSI V8 twin-turbo (Audi / Porsche / Bentley) engine have a timing chain or a timing belt?

Chain.

What oil does the 4.0 TFSI V8 twin-turbo (Audi / Porsche / Bentley) engine take?

0W-30 / 5W-30 · VW 502.00 / 504.00 · ~8.3–9.5 L · every 15,000 km.

What are the known problems with the 4.0 TFSI V8 twin-turbo (Audi / Porsche / Bentley) engine?

The faults with the highest risk: turbo oil strainer clogging → turbo failure (4.0 TFSI, to 2016) (80,000–180,000 km, €1,500–8,000); oil separator (PCV) failure (80,000–160,000 km, €300–800).

Which cars have the 4.0 TFSI V8 twin-turbo (Audi / Porsche / Bentley) engine?

Audi A6 (C7), Audi A7 (4G), Audi Q8 (4M), Audi A8 (D4).

Sources and notes

Faults, intervals and prices are indicative and collected from public sources and owner experience; always rely on the service book and a qualified workshop. Test statistics: DVSA – Anonymised MOT tests and results, Open Government Licence v3.0. Dutch tests: RDW Open Data (CC0). Owner complaints: NHTSA ODI (public domain). Recalls: DVSA Vehicle Safety Branch Recalls Database, OGL v3.0. Brand and model names are trademarks of their owners and are used only to describe the vehicles.

Updated 08/10/2026

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