Reconditioned Audi A4 2.0 TDI Engine

On the Audi A4 2.0 TDI, the engine code takes precedence over all other identification criteria

Between 2004 and 2015, Audi offered the 2.0 TDI on the A4 in no fewer than nine distinct engine codes: BPW, BRD, BRE, CABA, CAGB, CAHA, CGLB, CMGA and DEUA. These families span a range of power outputs (from 120 to 177 hp depending on the variant), different cylinder head architectures, injection systems and turbo geometries that are mutually incompatible. The vehicle's year and engine capacity alone are not sufficient to identify the correct unit.

Two generations, opposing architectures

The codes BPW and BRD belong to the pre-third-generation high-pressure Common Rail generation, characterised by a common-rail injection pump operating at 1,600 bar. The units in the CAHA, CAGB, CGLB, CMGA and DEUA series correspond to the EA189 and EA288 redesign, featuring a crankshaft and oil sump that are not interchangeable with the previous generation. A bare engine supplied without a confirmed engine code cannot be fitted without the risk of mechanical non-conformity.

Documented failure points on these units

The BRE and CABA units are particularly prone to EGR circuit fouling, which causes premature piston ring wear and a measurable loss of compression. On the CAHA and CAGB codes, failure of the variable-geometry turbocharger frequently results in metal swarf being projected into the bottom end of the engine, making a simple overhaul insufficient. In all cases, the replacement covers the bare engine: ancillary components (turbo, pump, injectors) remain those of the vehicle.