40 / 45 / 50 TDI (2.0 EA288 / 3.0 EA897)
2018–2024 · diesel · 1968cc · 204hp
Engine codes: DETA, DEWA, DMTA
Reliability, common problems and owner reviews for the Audi A6 C8 40 / 45 / 50 TDI (2.0 EA288 / 3.0 EA897). Check this before you buy used.
The TDI diesels are the high-mileage A6 C8 stars — the 2.0 TDI (40 TDI, EA288 — shared with the A4/Q5) and the superb 3.0 V6 TDI (45/50 TDI, EA897 with 48V mild-hybrid). Both are strong, exceptionally economical and ideally matched to the executive A6, with quattro. Standard modern-diesel cautions: DPF on short trips, EGR, twin-dosing AdBlue/SCR (more sensors/pumps), injector attention, and on the V6 the usual higher repair complexity. The 3.0 V6 TDI is one of the finest long-distance engines made; the 2.0 TDI is the value high-miler. A motorway-driven, serviced car is a genuine 300k long-hauler. Buy on oil, DPF and AdBlue history.
Same engine, other cars
This is the same physical engine (DETA) sold under different names across brands. Reliability is broadly shared — cross-check these:
Known Issues
DPF clogs and EGR soots on short trips; twin-dosing AdBlue/SCR has more parts to fail.
Fix / Workaround: Motorway regens; clean EGR; diagnose SCR.
Repair cost: €300–€1400
Typically appears after: 140,000 km
Injector attention at high miles; V6 carries higher repair complexity/cost.
Fix / Workaround: Injector test; budget for V6 jobs.
Repair cost: €250–€1600
Typically appears after: 180,000 km
Mileage Thresholds
After 280,000 km: 300k-capable executive diesel.
Pre-Purchase Checklist
- ☐3.0 V6 TDI is superb
- ☐2.0 TDI is the value high-miler
- ☐Oil + DPF + AdBlue history
Frequently asked questions
Is the Audi A6 C8 40 / 45 / 50 TDI (2.0 EA288 / 3.0 EA897) reliable?
Maint. Sensitive — The TDI diesels are the high-mileage A6 C8 stars — the 2.0 TDI (40 TDI, EA288 — shared with the A4/Q5) and the superb 3.0 V6 TDI (45/50 TDI, EA897 with 48V mild-hybrid). Both are strong, exceptionally economical and ideally matched to the executive A6, with quattro. Standard modern-diesel cautions: DPF on short trips, EGR, twin-dosing AdBlue/SCR (more sensors/pumps), injector attention, and on the V6 the usual higher repair complexity. The 3.0 V6 TDI is one of the finest long-distance engines made; the 2.0 TDI is the value high-miler. A motorway-driven, serviced car is a genuine 300k long-hauler. Buy on oil, DPF and AdBlue history.
What are the common problems and reviews for the Audi A6 C8 40 / 45 / 50 TDI (2.0 EA288 / 3.0 EA897)?
The most commonly reported problems: DPF / EGR / twin AdBlue, Injector / V6 complexity.
Is a used Audi A6 C8 40 / 45 / 50 TDI (2.0 EA288 / 3.0 EA897) worth buying?
Fine if serviced correctly — but it punishes neglect hard. History and the right consumables matter.