Audi S5 V8 Engine for Sale | OEM Used Audi 4.2 Liter FSI V8 Engine for Audi S5

Description

About the Audi S5 V8 Engine

Looking for a replacement Audi S5 V8 engine? Part Nests sources OEM used Audi 4.2L FSI V8 engines for the prestigious Audi S5 B8, RS4 B7, and R8 4.2 V8 performance applications. The Audi 4.2 FSI V8 is one of the most legendary modern Audi performance engines, featuring high-revving naturally aspirated character (8,250-8,500 RPM redline on RS4 and R8 tunes), FSI direct injection, and outputs ranging from 354 HP in the S5 tune to 420 HP in the RS4 / R8 tune. The 4.2 FSI V8 represents a distinct generation of Audi V8 engineering, separate from the newer 4.0 TFSI twin-turbo V8 (the engine used in the Bentley V8 per our listing and in Audi RS6 / RS7 / S6 / S7 / S8 modern variants).

Engine Overview: Audi 4.2 FSI V8 Architecture

• Displacement: 4.2 liters (4,163 cc)
• Configuration: V8 (two banks of 4 cylinders at 90 degrees)
• Power Output: 354 HP (Audi S5 B8 tune) up to 430 HP (Audi R8 4.2 V8 LMS racing-derived tune)
• Peak Torque: 325-317 lb-ft depending on application
• Redline: Approximately 7,000 RPM (S5 tune) up to 8,250-8,500 RPM (RS4 / R8 tunes – high-revving NA character)
• Cylinder Head: Aluminum, DOHC per bank with variable valve timing
• Block: Aluminum
• Fuel System: FSI (Fuel Stratified Injection) – Audi’s direct injection technology with high-pressure HPDI fuel pump
• Naturally aspirated: NO turbocharger (this is the NA 4.2 FSI V8; distinct from the newer 4.0 TFSI twin-turbo V8)
• Compression Ratio: Approximately 12.5:1 (high compression typical for NA performance)
• Variable valve timing: Yes, variable valve timing on intake and exhaust camshafts
• Timing drive: Timing chain
• Production: Approximately 2006-2015 across Audi performance applications
• Origin: German-engineered, manufactured by Audi at the Gyor (Hungary) and Neckarsulm (Germany) facilities

Audi 4.2 FSI V8 vs 4.0 TFSI V8 Distinction (Critical Buyer Note)

The Audi 4.2 FSI V8 (this listing) and the Audi 4.0 TFSI V8 are DIFFERENT Audi V8 engine families and represent distinct generations:

• Displacement: 4.2 FSI V8 4.2L vs 4.0 TFSI V8 4.0L
• Forced induction: 4.2 FSI V8 (this listing) is NATURALLY ASPIRATED; 4.0 TFSI V8 is TWIN-TURBOCHARGED
• Fuel system: Both use direct injection but tuned differently for NA vs forced induction
• Power character: 4.2 FSI V8 high-revving NA with 8,250-8,500 RPM redline (in RS4 / R8 tunes); 4.0 TFSI V8 turbocharged with lower redline but higher peak power
• Production era: 4.2 FSI V8 2006-2015 vs 4.0 TFSI V8 2012 plus (some overlap)
• Applications: 4.2 FSI V8 in Audi S5 B8 / RS4 B7 / R8 4.2 V8 (this listing’s applications); 4.0 TFSI V8 in Audi S6 / S7 / S8 / RS6 / RS7 / Bentley Continental GT V8 / Flying Spur V8 / Bentayga V8 / Porsche Panamera Turbo / Lamborghini Urus
• Cross-application: 4.2 FSI V8 and 4.0 TFSI V8 are NOT directly interchangeable; cross-application requires substantial work including different engine bays / fuel systems / ECU / cooling
• Calling to verify: Call (855) 634-4447 with your specific application year to verify variant before ordering

Audi 4.2 FSI V8 Applications

• Audi S5 B8 (2008-2012): Primary US-market S5 application; 354 HP / 325 lb-ft; sports coupe with quattro AWD
• Audi RS4 B7 (2006-2008): High-performance RS4 sedan/Avant wagon with the most aggressive NA tune of the 4.2 FSI V8; 420 HP / 317 lb-ft; 8,250 RPM redline
• Audi R8 4.2 V8 (2007-2015): The R8 supercar mid-engine application; 420-430 HP across production years; the R8 is a unique application of this engine in mid-engine configuration
• Audi S4 B7 (some variants): Some S4 B7 variants used the 4.2 V8 (the S4 transitioned from V8 to supercharged V6 in later generations)
• Audi A8 (some variants): Some A8 luxury sedan variants used 4.2 V8 architecture (though A8 typically used different V8 generations)
• NOT current Audi performance applications: The 4.2 FSI V8 has been phased out in favor of the 4.0 TFSI V8 (turbocharged) and other modern Audi powertrains

High-Revving NA Character Significance

The Audi 4.2 FSI V8 (especially in RS4 and R8 tunes) is one of the most legendary modern high-revving naturally aspirated V8 engines:

• 8,250-8,500 RPM redline (RS4 / R8 tunes): The 4.2 FSI V8 in RS4 and R8 tunes revs to 8,250-8,500 RPM, exceptionally high for a road-car V8
• Race-derived heritage: The R8 LMS racing program derived the high-revving tune for the road car R8 4.2 V8
• NA performance character: NA engines are widely regarded as having more direct throttle response, more linear power delivery, and a more visceral high-RPM sound than turbocharged equivalents – the 4.2 FSI V8 exemplifies these NA performance virtues
• Lamborghini Gallardo relationship: The Audi R8 4.2 V8 shares architectural heritage with the Lamborghini Gallardo’s V10 engine family (both used Audi-Lamborghini engine architectures); the V8 and V10 derive from related design lineage
• Enthusiast appreciation: The 4.2 FSI V8 RS4 B7 (2006-2008) is widely regarded by Audi enthusiasts as one of the greatest Audi engines ever produced for its high-revving NA character and balance

Common Audi 4.2 FSI V8 Failure Modes

• Direct injection carbon buildup: Standard direct-injection pattern requiring walnut shell blasting service every 60,000-100,000 miles; budget for this service
• Timing chain tensioner failure (CRITICAL): The 4.2 FSI V8 has documented timing chain tensioner failures, particularly on RS4 B7 applications; chain rattle at startup is the warning sign; proactive tensioner replacement is recommended
• HPDI high-pressure fuel pump failure: The mechanical HPDI fuel pump can fail
• Oil consumption: Some 4.2 FSI V8 examples (especially high-mileage RS4 B7) exhibit elevated oil consumption
• Cooling system age: 10-20 plus year old engines have aged cooling system components
• Coil pack failure: The 8 individual coil packs can fail; common service item
• FSI fuel system contamination: The FSI direct injection system is sensitive to fuel quality
• High-RPM operation wear: Owners who regularly operate at high RPM (the 4.2 FSI V8’s natural element) experience accelerated wear on various components

Audi Engine Context

The Audi 4.2 FSI V8 (this listing) is one of several Audi-related engines in our catalog. The Bentley V8 engine (our listing) is the Volkswagen-Audi-Bentley 4.0 TFSI twin-turbo V8 – a related but distinct family of Volkswagen Group V8 engine (the modern turbocharged V8 successor in many applications). The Bentley W12 engine (our listing) is the Volkswagen-Bentley 6.0L twin-turbo W12. Audi A/C system parts for various Audi applications are covered by our (Audi 4000 Quattro A/C Compressor), (Audi 80 Series A/C Condenser), (Audi 90 Series A/C Condenser Fan), (Audi A8 A/C Wiring Harness), (Audi A4 A/C Evaporator), and (Audi A7 A/C Hose) listings.

Vehicle Compatibility

4.2 FSI V8 Architecture Specifications

Why Buy From Part Nests

• Engine verified as Audi 4.2 FSI V8 (the legendary high-revving naturally aspirated 4.2L V8 with FSI direct injection)
• Year and generation confirmed (4.2 FSI V8 production approximately 2006-2015 across Audi performance applications)
• Application confirmed (Audi S5 B8 2008-2012, RS4 B7 2006-2008, R8 4.2 V8 2007-2015)
• Horsepower rating documented (354 HP S5, 420 HP RS4, 420-430 HP R8 4.2 V8)
• Compression and leak-down tested all 8 cylinders
• Both cylinder banks condition documented (V8 has 2 banks of 4 cylinders at 90 degrees)
• FSI direct injection system documented (Fuel Stratified Injection – Audi direct injection)
• High-revving NA character documented (8,250-8,500 RPM redline on RS4 / R8 tunes)
• Timing chain condition assessed (4.2 FSI V8 uses timing chain)
• Specialty heavy freight to all 50 states
• 15 day replacement warranty on internal defects
• Audi performance engine experience and 4.2 FSI V8 / 4.0 TFSI V8 distinction and timing chain tensioner concern knowledge from our support team
• Call (855) 634-4447 for application verification and to place your order.