The B8 S4 with its 3.0T supercharged V6 is a significant improvement over the V8 predecessor, but the platform still carries expensive carbon buildup issues, transmission cooler failures that can grenade the dual-clutch, and the dreaded timing chain tensioner problem that can destroy the entire engine if ignored.
Timing Chain Tensioner Failure Leading to Catastrophic Engine Damage
Occasional · high severity
Typical onset: 80,000-120,000 mi
Symptoms: Cold-start rattle for 1-2 seconds that progressively worsens, Check engine light with timing correlation codes (P0017, P0016), Metallic rattling from front of engine on startup, Loss of power or rough running if chains have jumped timing
Fix: Requires engine-out service to replace all three timing chains, tensioners, guides, and both cam adjusters. This is a 25-30 hour job. If chains have already failed and damaged pistons/valves, you're looking at engine rebuild or replacement. The revised tensioners (post-2012 part numbers) are mandatory.
Estimated cost: $5,000-8,000 for preventive replacement; $12,000-18,000 if engine internals are damaged
DSG Transmission Oil Cooler Failure and Clutch Pack Contamination
Common · high severity
Typical onset: 60,000-100,000 mi
Symptoms: Transmission slipping or shuddering during shifts, Metallic debris in transmission pan during service, Cooler leaking at crimped seams (visible ATF weeping), Harsh engagement from stop or jerky low-speed shifts
Fix: The transmission cooler fails internally, sending metal shavings through the mechatronic unit and contaminating clutch packs. Fix requires new cooler, complete fluid flush with special filter procedure, and often a new mechatronic unit. If caught early (cooler only), 4-6 hours. If clutches are damaged, transmission comes out for clutch replacement adding 12+ hours.
Estimated cost: $1,500-3,000 for cooler and flush; $5,000-7,000 if mechatronic or clutches need replacement
Direct Injection Carbon Buildup on Intake Valves
Common · medium severity
Typical onset: 60,000-80,000 mi initially, then every 40,000-60,000 mi
Symptoms: Rough idle and misfires at cold start, Loss of power and throttle response, Fuel trims out of range, misfire codes on multiple cylinders, Hesitation or stumbling under light acceleration
Fix: Direct injection means no fuel washing over intake valves. Requires walnut blasting the intake ports with supercharger and intake manifold removed. This is a 6-8 hour job. Some shops use chemical methods but walnut blasting is the gold standard.
Estimated cost: $800-1,400
Supercharger Nose Bearing and Coupler Wear
Occasional · medium severity
Typical onset: 100,000-140,000 mi
Symptoms: Whining or squealing from front of engine that changes with RPM, Bearing noise that's audible at idle and increases under boost, Vibration felt through throttle pedal under acceleration, Supercharger oil seeping from front seal
Fix: The Eaton TVS supercharger's input shaft bearing wears or the rubber coupler deteriorates. Supercharger must come off for rebuild. Some rebuild just the bearing and coupler (8-10 hours), others replace the entire nose cone. DIY-friendly if you have the tools, but alignment is critical.
Estimated cost: $1,200-2,500
Water Pump and Thermostat Housing Failure
Common · medium severity
Typical onset: 70,000-110,000 mi
Symptoms: Coolant leaking from front of engine or onto belly pan, Overheating or erratic temperature gauge readings, Low coolant warning light, Coolant smell in cabin or visible steam from hood
Fix: Plastic impeller water pumps fail, and the thermostat housing cracks at the mounting points. Always replace both together along with the coolant flange on the back of the head (another common leak point). The supercharger partially blocks access, adding time. 4-6 hours for the job.
Estimated cost: $900-1,600
PCV System Failure and Oil Consumption
Occasional · medium severity
Typical onset: 80,000-120,000 mi
Symptoms: Excessive oil consumption (1 quart per 1,000-2,000 miles), White smoke from exhaust on deceleration, Oil in intake tract or intercooler, Rough idle or vacuum-related misfires
Fix: The PCV valve and breather system clogs or the diaphragm in the valve cover fails, causing oil to be sucked into the intake. Requires valve cover removal and replacement of the integrated PCV components. While you're in there, replace the cam bridge seal (common leak). 3-5 hours per bank if doing both.
Estimated cost: $600-1,200 for both banks
Front Control Arm Bushings and Ball Joints
Common · low severity
Typical onset: 70,000-100,000 mi
Symptoms: Clunking over bumps from front suspension, Wandering steering or vague on-center feel, Uneven tire wear on inside edges, Alignment won't hold or goes out quickly
Fix: The pressed-in bushings in the lower control arms wear out, and Audi doesn't sell bushings separately—only complete arms. Some aftermarket options exist for bushing replacement only. Figure 3-4 hours to do both sides with alignment.
Estimated cost: $800-1,400 with OEM arms and alignment
Owner tips
Change DSG fluid every 40,000 miles with the filter—this prevents most transmission cooler issues if caught early
Listen for any cold-start rattle and address timing components immediately; waiting will cost you an engine
Budget for walnut blasting every 60,000 miles as preventive maintenance
Use quality synthetic 5W-40 oil (not 5W-30) and change every 5,000 miles to minimize carbon buildup and timing chain wear
Inspect and replace transmission mounts—they fail and cause driveline shudder that mimics clutch problems
Buy one only if timing chains and DSG cooler have been addressed with receipts, and budget $3,000-5,000 for deferred maintenance; otherwise, you're gambling with an $8,000 engine repair.
AI-assisted summary drawn from NHTSA recall data, our labor-times database, and platform knowledge. Not a substitute for a pre-purchase inspection on a specific vehicle.
Fitment notes: AGM battery required; located in trunk under spare tire well
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Every control module on the 2008-2012 Audi S4 — where it lives, replacement time, and what it takes to program a replacement. Modules marked dealer / factory tool won't work after a part swap alone — budget for programming.
⚠️ Separate modules for driver and passenger if equipped. Basic adaptation only.
Aftermarket tool coverage varies by software version and vehicle build — treat "aftermarket tool" rows as "usually possible" and verify against your tool maker's coverage list before promising a customer. Spot a wrong location or hour? Tell us — corrections ship fast here.
AIR BAGS:FRONTAL:PASSENGER SIDE:INFLATOR MODULE · 18V427000
2018-06-22 · EA15001
Volkswagen Group of America, Inc. (Volkswagen) is recalling certain 2005-2008 Audi A4 Sedan, A4 Avant, S4 Avant and S4 Sedan, 2007-2008 RS4 Sedan, 2004 RS4 Cabriolet, 2007-2009 A4 Cabriolet and S4 Cabriolet, 2005-2011 A6 Sedan, 2006-2011 A6 Avant, and 2007-2011 S6 Sedan vehicles. These vehicles are equipped with certain air bag inflators assembled as part of the passenger frontal air bag modules used as original equipment or replacement equipment. In the event of a crash necessitating deployment of the passenger frontal air bag, these inflators may explode due to propellant degradation occurring after long-term exposure to absolute humidity and temperature cycling.
Consequence: An inflator explosion may result in sharp metal fragments striking the driver or other occupants resulting in serious injury or death.
Remedy: Audi has notified owners, and dealers will replace the passenger frontal air bag with an alternate remedy part, free of charge. The recall began June 29, 2018. Owners may contact Audi customer service at 1-800-253-2834. Volkswagen's number for this recall is 69R7. Note: This recall supersedes recalls 16V382, 17V032 and 18V004 and includes vehicles that may have had their air bag previously replaced under one of those campaigns.
AIR BAGS:FRONTAL:PASSENGER SIDE:INFLATOR MODULE · 17V032000
2017-01-11 · EA15001
Volkswagen Group of America, Inc. (Volkswagen) is recalling certain 2009 Audi A4 Cabriolet, S4 Cabriolet, A6 Avant, A6 Sedan and S6 Sedan vehicles originally sold, or ever registered, in Arizona, Arkansas, Delaware, the District of Columbia, Illinois, Indiana, Kansas, Kentucky, Maryland, Missouri, Nebraska, Nevada, New Jersey, New Mexico, North Carolina, Ohio, Oklahoma, Pennsylvania, Tennessee, Virginia, and West Virginia, or "Zone B."
Additionally, unless included in "Zone B" above, Volkswagen is recalling certain 2005-2008 Audi A4 Avant, A4 Sedan, A6 Sedan, S4 Avant and S4 Sedan vehicles, 2007-2008 A4 Cabriolet, RS4 Sedan, S4 Cabriolet and S6 Sedan vehicles, and 2006-2008 A6 Avant and 2008 RS4 Cabriolet vehicles originally sold, or ever registered, in Alaska, Colorado, Connecticut, Idaho, Iowa, Maine, Massachusetts, Michigan, Minnesota, Montana, New Hampshire, New York, North Dakota, Oregon, Rhode Island, South Dakota, Utah, Vermont, Washington, Wisconsin, and Wyoming.
These vehicles are equipped with certain air bag inflators assembled as part of the passenger frontal air bag modules used as original equipment or replacement equipment. In the event of a crash necessitating deployment of the front air bags, these inflators may rupture due to propellant degradation occurring after long-term exposure to absolute humidity and temperature cycling.
Consequence: An inflator rupture may result in metal fragments striking the vehicle occupants resulting in serious injury or death.
Remedy: Audi will notify owners, and dealers will replace the passenger frontal air bag inflator, free of charge. The recall began March 30, 2018. Owners may contact Audi customer service at 1-800-253-2834. Note: This recall has been superseded by recall number 18V427.
Performance
Horsepower
333hp
Torque
325lb-ft
0–60 mph
4.9sec
Quarter mile
13.4sec
Top speed
155mph
Capability & size
Curb weight
4,145lb
Wiper blades
B8 generation sedan. Some sources show 22/19 configuration.
Size-standard part numbers — verify your connector type before buying. Rear blades are model-specific; check the package's vehicle list.
Fuel economy figures are EPA data via fueleconomy.gov (median across matching trims). Performance figures are compiled estimates for the 2009 Audi S4 3.0L Supercharged V6 and can vary by trim.
🔧 Database maintained under the daily editorial review of Chris Hackleman · Master Technician · 20+ years and Jeff Moore · Master Lexus & Toyota Mechanic · 20+ years.