Description
Audi S5 V8 Engine for Sale: Unmatched Performance and Reliability
The Audi S5 V8 engine with its perfect blend of power and refinement is another testimony to how good German automotive engineering can be. The V8 engine in the Audi S5 propels it from 0-60 mph in approximately 4.9 seconds, with a driving feel that few vehicles can match. The high-revving NA V8 sound is music to the ears of any enthusiast, and the way the car hauls itself from any speed is satisfying in itself.
The Audi S5 V8 engine for sale here is not just about power; it showcases reliability and longevity. It’s built with the precision and quality that Audi is known for. Whether you are cruising the highway or driving spirited backroads, this engine delivers.
Engine Overview: Audi 4.2 FSI V8
The Audi S5 V8 is the 4.2 FSI V8 engine (engine codes BNS and CAUA) that powered the B8 chassis Audi S5 Coupe and Cabriolet from 2008 to 2012. Specifications:
Critical Disambiguation: B8 S5 V8 vs Post-2012 Supercharged V6 S5
This is the most important purchasing distinction for the Audi S5. The Audi S5 model name covers TWO completely different engines across generations:
B8 S5 V8 (2008-2012) , THIS LISTING
Engine: 4.2 FSI V8 (BNS/CAUA)
HP: 354 HP
Aspiration: Naturally aspirated
Character: High-revving V8 sound, 7,200 RPM redline
Performance: 0-60 in ~4.9 seconds
B8.5 / B9 S5 V6 Supercharged (2013-Present)
Engine: 3.0 TFSI V6 supercharged (CGWC/CREC)
HP: 333-349 HP
Aspiration: Supercharged
Character: V6 with supercharger whine
Performance: 0-60 in ~4.7 seconds (slightly faster despite less HP due to torque)
For replacement applications: verify which engine your S5 has. The V8 and supercharged V6 are NOT interchangeable.
The VW-Audi Group 4.2 FSI V8 Architecture
The Audi S5 V8 is part of one of Audi’s most important performance V8 engine families. The same fundamental 4.2 FSI V8 architecture powers:
Audi S5 V8 (This Listing)
Application: B8 S5 Coupe and Cabriolet (2008-2012)
HP: 354 HP
Character: Refined sports coupe tuning
Audi RS4 B7 (2006-2008)
Application: RS4 B7 sedan and Avant (wagon)
HP: 420 HP (the more aggressively tuned variant)
Character: RS-tuned for maximum performance
Differences: Different ECU, intake, exhaust, and supporting components
Audi R8 V8 (2007-2015)
Application: R8 V8 supercar
HP: 420 HP (R8-specific tuning)
Character: Mid-engine supercar configuration
Differences: Different ECU, intake/exhaust, oil system for mid-mount, supporting components
The shared 4.2 FSI V8 architecture means all three engines use the same fundamental block, heads, FSI system, and basic V8 design , with Audi RS / R8-specific tuning for higher output. For replacement applications, the S5-specific variant should be matched (BNS or CAUA engine codes for the S5).
FSI Direct Injection Technology
The “FSI” in 4.2 FSI V8 stands for Fuel Stratified Injection, Audi’s direct injection technology:
What FSI Does
Fuel injected directly into combustion chambers (not into intake ports)
High pressure injection (200+ bar)
Multiple injection events per combustion cycle
Stratified charge operation at part-throttle for efficiency
Homogeneous charge operation at full-throttle for power
Benefits Over Port Injection
Higher compression possible (enables 12.5:1 in 4.2 FSI V8)
More power from same displacement
Better fuel economy at part-throttle
Lower emissions with optimized combustion
Trade-Off , Carbon Buildup
FSI direct injection doesn’t wash intake valves with fuel (port injection does)
Result: Carbon builds up on intake valves over time
Symptoms: Reduced low-RPM power, rough idle
Service: Walnut blasting at 60,000-100,000 miles
Cost: $1,500-3,000 for proper service
Vehicle Applications
Audi S5 Coupe B8 (2008-2012)
The original 4.2 FSI V8 S5 application:
Body style: 2-door sports coupe
Drivetrain: Audi quattro AWD standard
Transmissions: 6-speed manual, S Tronic 7-speed DCT, Tiptronic 6-speed automatic
Performance: 0-60 in ~4.9 seconds
Production: 2008-2012 US market
Audi S5 Cabriolet B8 (2010-2012)
The convertible variant of the V8 S5:
Body style: 2-door soft-top convertible
Drivetrain: Audi quattro AWD standard
Transmissions: S Tronic 7-speed DCT or Tiptronic 6-speed
Performance: 0-60 in ~5.1 seconds (slightly slower than coupe due to weight)
Production: 2010-2012 US market
Common 4.2 FSI V8 Service Items (Honest Disclosure)
The 4.2 FSI V8 has several significant documented service areas that buyers must understand:
Timing Chain Tensioner Failures (THE PRIMARY 4.2 FSI V8 CONCERN)
This is the most well-documented and concerning service area for the 4.2 FSI V8.
#### What Happens
Audi 4.2 FSI V8 uses timing chains at the rear of the engine (between engine and transmission)
The chain tensioners (multiple) can fail over time
Failed tensioners allow chain slap and eventual chain skip
In severe cases, complete engine destruction
#### Symptoms
Cold-start rattle from rear of engine
Persistent timing chain rattle
Check engine light with cam/crank correlation codes
In severe cases, engine no-start or running poorly
#### Why It’s Severe
Engine-out service required: The chains are at the REAR of the engine
Transmission must be removed to access the chains
Significant labor: 25-40+ hours typical
Service cost: $4,000-8,000+ when performed properly
#### Audi TSB and Updates
Audi issued multiple updated tensioner designs throughout production
Later production examples may have updated tensioners
Replacement engines should have current updated tensioner design ideally
#### Our Inspection Approach
Cold-start rattle assessment: Listening test for tensioner symptoms
Cam/crank correlation check: ECU scan for timing-related codes
Engine code documentation: BNS vs CAUA for service history context
Honest disclosure: We disclose any concerns identified
Carbon Buildup on Intake Valves
Typical FSI direct-injection issue:
Symptoms: Reduced low-RPM power, rough idle, misfire codes
When: 60,000-100,000 miles typical
Service: Walnut blasting service ($1,500-3,000)
High Oil Consumption
The 4.2 FSI V8 is known for oil consumption:
Common rate: 1 quart per 1,000-3,000 miles at high mileage
Causes: Piston ring wear, valve seal wear
Mitigation: Regular oil top-off, quality 5W-30 or 5W-40 synthetic
Severe cases: May indicate need for piston/ring service
Water Pump Failures
Service interval: 60,000-100,000 miles
Service: $500-1,000 typical
Cost includes: Coolant flush, thermostat often replaced together
Coil Pack Failures (8 Coils)
Symptoms: Misfire codes, rough running
Service: $80-150 per coil
Multiple failures: Common across engine lifetime
High-Pressure Fuel Pump (HPFP)
Service area for FSI engines: Documented HPFP failures
Service cost: $1,000-2,000 typical
Jamie Lee (verified owner) –
Picked up the Audi S5 V8 engine from Vaz Auto Solutions. It performs well with impressive power and smooth operation, but the fuel economy is a bit on the high side. While it’s a strong engine with great performance, the cost of running it can add up. It’s a solid choice if you’re after that V8 experience, but just be prepared for more frequent trips to the gas station.
Alex Ramirez (verified owner) –
The Audi S5 V8 engine from Vaz Auto Solutions is a performance enthusiast’s dream! This powerhouse delivers exhilarating acceleration and a thrilling exhaust note that’s music to the ears. The engine’s responsiveness and sheer power make every drive a pleasure, whether you’re on the track or just cruising. It’s smooth, robust, and offers that classic V8 growl.