The fourth generation of Transporter, Caravelle, and Multivan minibuses were equipped with the 2.5-liter Volkswagen AAF or T4 2.5 gasoline engine, which was manufactured between 1990 and 1993. The ACU, AEN, and AEU indices are used to identify updated versions of this power unit.
AAF and AET gasoline engines from the EA153 series.
Specifications
| Production years | 1990-1993 |
| Displacement, cc | 2461 |
| Fuel system | distributed injection |
| Power output, hp | 110 |
| Torque output, Nm | 190 |
| Cylinder block | cast iron R5 |
| Block head | aluminum 10v |
| Cylinder bore, mm | 81 |
| Piston stroke, mm | 95.5 |
| Compression ratio | 8.5 |
| Features | SOHC |
| Hydraulic lifters | yes |
| Timing drive | belt |
| Phase regulator | no |
| Turbocharging | no |
| Recommended engine oil | 5W-40 |
| Engine oil capacity, liter | 5.0 |
| Fuel type | petrol |
| Euro standards | EURO 1 |
| Fuel consumption, L/100 km (for VW Transporter 1992) — city — highway — combined |
17.4 9.8 12.1 |
| Engine lifespan, km | ~350 000 |
| Weight, kg | 180 |
The engine was installed on:
- Volkswagen Transporter T4 (7D) in 1990 – 1994.
Disadvantages of the VW AAF engine
Many owners convert this dependable but gluttonous engine to gas.
Inadequate gas equipment setting is linked to many engine issues.
Additionally, issues with the Digifant system could be the reason for unstable operation.
Examine the MAP sensor first, then every rubber hose to find the culprit.
The valves do not bend here, but the timing belt and auxiliary units still occasionally fly.