The Audi EA837 series of 6-cylinder V-engines has been produced by the company since 2004 and is installed on almost all of the group’s models: from the compact A4 to the Q7 crossovers. These engines are divided into four generations, differing in the type of injection and the presence of turbocharging.
In 2004, the engines of the EA835 family were replaced by new power units of the EA837 series. According to the design, there is a silumin block of the V6 type already without liners with a cylinder camber angle of 90°, two aluminum DOHC cylinder heads with roller rocker arms, as well as hydraulic compensators and a sophisticated timing drive with four chains, two intermediate gears, a balancer, and all this was located on the rear side, so to replace the chains the motor had to be removed. Another thing to note here is the sophisticated intake manifold with two rows of dampers.
The series included a 2.4-liter engine with distributed injection and phase regulators at the intake, and four more power units with FSI direct injection and phase regulators on all shafts:
Already in 2006, production of the second generation of engines from the EA837 family began. These units were distinguished by the presence of a system for varying the degree of opening of the intake valves AVS, a two-stage oil pump, an injection pump with a roller tappet and an updated timing drive with more reliable tensioners, trioval sprockets and new roller chains. This time, all power units of this family were equipped with an FSI direct injection system.
The updated series consisted only of engines with direct fuel injection of 2.8 and 3.2 liters:
In 2008, the third generation V6 engines debuted on the restyled version of the A6 model, which were primarily distinguished by the presence of an Eaton compressor with a built-in cooler. The aluminum block, heads and timing chain drive were redesigned for greater power, but the proprietary AVS system and phase regulators on the exhaust shafts had to be abandoned. The control here is carried out by a Siemens Simos 8 ECU, and a Hitachi HDP 3 fuel injection pump is used.
Thanks to the adjustment of the degree of boost, many modifications of such engines were created:
There are also two hybrid versions with the index CGEA and CGFA for the Touareg Hybrid model.
In 2013, the second generation of 3.0 TFSI engines or the fourth generation for the EA837 appeared. The main difference between the new engines was the change from direct fuel injection to combined, that is, a second row of injectors was added that inject fuel into the intake manifold. They also returned the exhaust phase regulators and added an electromagnetic clutch to the compressor, and the cylinder block, cylinder head and connecting rod-piston group were revised to accommodate the compression ratio, which had increased from 10.5 to 10.8. Another important innovation is the replacement of the alusil coating with cast iron sleeves.
In 2016, the latest turbocharged V6 units of the EA839 family were introduced and they gradually replaced the EA837 series; the last to abandon them was the Q7 crossover in 2020.
The 2.4-liter Audi BDW 2.4 MPI injection engine was assembled at the factory from 2004 to 2008 and installed only on the popular A6 model in the C6 body in a modification before restyling. This unit was the only engine in the line with distributed fuel injection.
The company assembled the 3.2-liter 24-valve Audi AUK 3.2 FSI engine from 2004 to 2010 and installed it on such popular models of the German concern as the A4 B7, A6 C6 or A8 D3. This power unit has several analogues at once with other BKH, BPK and BYU indices.
The 2.8-liter Audi BDX 2.8 FSI engine was produced at the company’s factories from 2006 to 2010 and was installed only on two models of the German concern: the A6 in the back of the C6 or the A8 in the back of the D3. This power unit has several analogues at once under the …
The 3.0-liter turbocharged Audi CAJA 3.0 TFSI engine was produced from 2008 to 2011 and was installed only on the restyled version of the sixth generation A6 model with all-wheel drive. There was an analogue of this power unit for the American market under the CCAA index.
The 3.0-liter Audi CGWA 3.0 TFSI engine was assembled at the concern’s factories from 2009 to 2013 and was installed on the fourth-generation all-wheel drive modification of the A8 model before restyling. This power unit was essentially a slightly updated version of the engine under the CAJA index.
The 3.0-liter Audi CGWB 3.0 TFSI gasoline engine was assembled at the factory from 2010 to 2012 and installed on all-wheel drive versions of the popular A6 and A7 models in the C7 body before restyling. There was also a more powerful version of this power unit under a different CGWD index.
The 3.0-liter Audi CREC 3.0 TFSI turbo engine has been produced at the concern’s factories since 2014 and is installed on such popular models of the German company as the A6, A7 and the Q7 crossover. This unit is equipped with combined fuel injection and belongs to the EA837 EVO series.
