The 2.5-liter Audi BAU 2.5 TDI diesel engine was assembled by the company from 2003 to 2005 and belonged to the updated B-series, that is, the timing rockers are equipped with special rollers. This unit was most often found under the hood of such popular models as the A4 B6 and A6 C5.
EA330 family: AFB, AKE, AKN, AYM, BAU, BDG, BDH.
Specifications
| Production years | 2003-2005 |
| Displacement, cc | 2496 |
| Fuel system | direct injection |
| Power output, hp | 180 |
| Torque output, Nm | 370 |
| Cylinder block | cast iron V6 |
| Block head | aluminum 24v |
| Cylinder bore, mm | 78.3 |
| Piston stroke, mm | 86.4 |
| Compression ratio | 18.5 |
| Features | 2 x DOHC |
| Hydraulic lifters | yes |
| Timing drive | belt |
| Phase regulator | no |
| Turbocharging | VGT |
| Recommended engine oil | 5W-30 |
| Engine oil capacity, liter | 6.0 |
| Fuel type | diesel |
| Euro standards | EURO 3 |
| Fuel consumption, L/100 km (for Audi A6 2004) — city — highway — combined |
11.3 6.2 8.1 |
| Engine lifespan, km | ~300 000 |
The engine was installed on:
- Audi A4 B6 (8E) in 2003 – 2004;
- Audi A6 C5 (4B) in 2003 – 2005;
- Volkswagen Passat B5 (3B) in 2003 – 2005.
Disadvantages of the Audi BAU engine
- Most engine problems are related to failures of the electronically controlled injection pump VP44;
- There are many cases on the net when newfangled hollow camshafts burst;
- Also, this motor is extremely prone to oil leaks, especially from under the valve cover;
- At high mileage, the geometry of the turbine or the viscous coupling bearing often wedges;
- Bad oil quickly damages hydraulic lifters and pressure reducing valves.
Frequently asked questions about the Audi BAU
How much power does the Audi BAU make?
The Audi BAU develops 180 hp and 370 Nm of torque.
How much oil does the Audi BAU take and which one?
Engine oil capacity: 6.0 liters. Recommended oil: 5W-30.
Does the Audi BAU have a timing belt or chain?
The Audi BAU uses a timing belt.
Is the Audi BAU turbocharged?
Yes, the Audi BAU is turbocharged (VGT).
Does the Audi BAU need valve clearance adjustment?
No, the Audi BAU has hydraulic lifters, so the valve clearances do not need to be adjusted.
How long does the Audi BAU last?
The typical lifespan of the Audi BAU is ~300 000 km with proper maintenance.
What is the fuel consumption of the Audi BAU?
Audi A6 2004: city 11.3, highway 6.2, combined 8.1 L/100 km.
What cars was the Audi BAU installed on?
Audi A4 B6 (8E) in 2003 - 2004; Audi A6 C5 (4B) in 2003 - 2005; Volkswagen Passat B5 (3B) in 2003 - 2005.
What are the common problems of the Audi BAU?
Most engine problems are related to failures of the electronically controlled injection pump VP44. There are many cases on the net when newfangled hollow camshafts burst. All known problems.
