3.0 TDI V6 quattro (ASB/CDYA)
2004–2011 · diesel · 2967cc · 233hp
Engine codes: ASB, BMK, CDYA
Reliability, common problems and owner reviews for the Audi A6 C6 3.0 TDI V6 quattro (ASB/CDYA). Check this before you buy used.
The 3.0 TDI quattro — widely regarded as the reference modern diesel of its day: strong, smooth and durable with regular (15,000 km) oil changes. The post-2008 versions are especially solid. Watch intake carbon/EGR and DPF, plus high running costs, but the core engine is excellent.
Same engine, other cars
This is the same physical engine (ASB) sold under different names across brands. Reliability is broadly shared — cross-check these:
Known Issues
Carbon and EGR clogging on the intake with age.
Fix / Workaround: Clean intake/EGR.
Repair cost: €200–€800
Typically appears after: 180,000 km
DPF blocks on short trips.
Fix / Workaround: Motorway runs; clean/replace.
Repair cost: €300–€1200
The 3.0 TDI's timing chains sit at the gearbox side, so worn tensioners/guides (rattle on cold start) mean an engine-out repair. Chains don't snap often, but when neglect lets them jump, the engine is scrap. The single most expensive risk on an otherwise robust V6.
Fix / Workaround: Listen for cold-start rattle from the rear of the engine; walk away or budget a four-figure job if present. Verified long oil-change discipline is the best protection.
Repair cost: €2500–€4500
Typically appears after: 180,000 km
Direct injection means the intake tract carbons up; the swirl-flap linkage and motors stick and log faults, hurting low-rpm torque. A known maintenance point on all generations of this V6.
Fix / Workaround: Walnut-blast the intake and replace/repair the flap motors when codes appear. Not urgent, but factor it into the price.
Repair cost: €300–€900
Typically appears after: 150,000 km
Mileage Thresholds
After 250,000 km: Durable with 15k-km oil changes.
After 200,000 km: Cold-start chain rattle check is mandatory from here on — rear-mounted chains make this the deciding factor between a bargain and a money pit.
Fault Codes to Scan
Pre-Purchase Checklist
- ☐Regular (15k km) oil-change history
- ☐DPF/EGR history; prefer motorway use
- ☐The reference C6 diesel
Frequently asked questions
Is the Audi A6 C6 3.0 TDI V6 quattro (ASB/CDYA) reliable?
Reliable — The 3.0 TDI quattro — widely regarded as the reference modern diesel of its day: strong, smooth and durable with regular (15,000 km) oil changes. The post-2008 versions are especially solid. Watch intake carbon/EGR and DPF, plus high running costs, but the core engine is excellent.
What are the common problems and reviews for the Audi A6 C6 3.0 TDI V6 quattro (ASB/CDYA)?
The most commonly reported problems: Intake carbon / EGR, DPF clogging, Timing chain tensioner wear — chains are at the REAR of the engine, Intake manifold swirl-flap motors and carbon buildup.
Is a used Audi A6 C6 3.0 TDI V6 quattro (ASB/CDYA) worth buying?
Minor issues only, easy to maintain, no design flaws. A safe used buy.