Description

B5 S4 Engine

The B5 S4 engine is a 2.7-liter twin-turbocharged, 30-valve, 90° V6, identified by engine codes like AGB or AZB. Known for its power, it is a popular engine with enthusiasts but is also notorious for reliability issues related to heat buildup in its tight engine bay, which can cause components like wiring, sensors, and turbos to degrade over time.

Engine specifications

• Type: 2.7-liter, 90° V6, twin-turbocharged (“biturbo”)
• Valvetrain: DOHC, 30-valve
• Block: Cast iron cylinder block
• Cylinder Heads: Lightweight aluminum alloy
• Engine Codes: AGB, AZB, APB