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Audi · Known Issues

2011 Audi S4 Problems: 6 Known Issues

2011 model year · 107+ owner reports · Updated September 2026

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Issue summary

According to Au7o's analysis of 107+ owner reports, the 2011 Audi S4 has 6 documented known issues, with 2 rated critical. The most serious are Fuel Rail or Seal Leak Creates Fire Risk (Recall 15V019 / 24AP) and 0B5 DL501 S tronic Mechatronic Unit Failure - Harsh Shifts, Erratic Gear Selection and Limp Mode ($1,800-$7,000 repair). The most commonly reported issue is Thermostat Housing Failure and Coolant Leak with 107 owner reports. Across all issues with published estimates, repair costs range from $300 to $7,000. DIY maintenance guides at au7o.io.

In This Article

  • S4 Fuel System1
  • S4 Transmission1
  • S4 Engine3
  • S4 Cooling1
  • Recalls5
  • FAQ
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In This Article

  • Fuel System1
  • Transmission1
  • Engine3
  • Cooling1

All 6 Known Issues

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On the 2011-2012 Audi S4 3.0 TFSI, certain 2011-2012 S4 fuel-injection systems can leak at the fuel rails or corresponding seals, creating a fire risk near an ignition source.

This issue also affects: Audi Q7, Audi A7

Common Symptoms

  • Fuel odor
  • Visible fuel leakage

How to Fix

Check the VIN and campaign history. Audi dealers replace the fuel rails and corresponding seals free of charge under campaign 24AP. If fuel odor or leakage is present, stop driving and arrange immediate inspection.

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NHTSA Verified
High ConfidenceVerifiedReviewed Jul 2026

On the 2010-2016 Audi S4, s4s ordered with the 7-speed S tronic dual-clutch use the 0B5 (DL501) gearbox, whose mechatronic control unit - the valve body with its integrated solenoids, pressure sensors and TCU - is a documented weak point in high-torque applications like the S4. Failures start as harsh or jerky engagement and occasional gear-selection errors, then progress: limp home mode, sticking in gear, loss of half the gears, or no reverse. Root causes are solenoid regulation faults, clutch pressure-sensor faults, internal overheating, and speed-sensor faults. Because the S4's torque output loads the unit harder than the A4 applications sharing the same gearbox, S4 owners see it disproportionately. This is a transmission-specific issue - manual-transmission S4s are unaffected.

Common Symptoms

  • Harsh, jerky or clunky gear engagement
  • Erratic or wrong gear selection
  • Transmission malfunction warning on the dash
  • Limp home mode / stuck in one gear
  • Loss of reverse or of half the gear set
  • Shuddering when pulling away

How to Fix

No recall. Diagnosis must start with a proper scan and a clutch adaptation/basic-settings check, not parts swapping. Genuine mechatronic faults are repaired either by rebuilding the existing unit (solenoid/valve body repair, which specialists offer at a fraction of dealer cost) or by fitting a replacement mechatronic unit, which then requires coding and adaptation to the car. Keeping the DSG fluid and filter service on schedule (roughly every 40,000 miles) is the main preventative lever - overheated, degraded fluid is a repeat contributor. Some owners report repeat failures even after replacement, so confirm the repairer addresses the cause, not just the unit.

Typical repair cost:$1,800 - $7,000

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Community Reported
Medium ConfidenceVerifiedReviewed Aug 2026

On the 2010-2016 Audi S4, the B8/B8.5 S4's Eaton TVS roots supercharger drives its rotor pack through a plastic coupler disc between the drive snout and the driven rotor. Over time the drive holes in that plastic coupler elongate and wear, and the slop shows up as a distinct rattling / marbles-in-a-can noise from the front of the engine at idle and low rpm, usually going away as revs rise. This is a wear item specific to the supercharged 3.0 TFSI (B8/B8.5) - it does not exist on the B9's turbocharged EA839, the B6/B7 V8, or the B5 2.7T. It is not immediately dangerous, but ignoring it lets the wear load the supercharger's bearings and shaft seals, turning a coupler job into a full blower rebuild.

Common Symptoms

  • Rattling / 'bag of marbles' noise from the front of the engine at idle
  • Noise quiets or disappears above idle
  • Rotational play felt at the supercharger input shaft with the snout removed
  • In late stages, whine or oil weeping from the supercharger snout

How to Fix

No recall or bulletin. The coupler is diagnosed by removing the snout and rotating the input shaft by hand to feel the rotational play. The fix is replacing the coupler (and inspecting the snout bearings and oil) - far cheaper than a supercharger rebuild. Do the job as soon as the rattle appears, not after seals start weeping. Snout oil should be checked at the same time since a dry snout accelerates the same failure.

Typical repair cost:$400 - $1,500

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Community Reported
Medium ConfidenceVerifiedReviewed Aug 2026

On the 2010-2016 Audi S4, the supercharged 3.0 TFSI's crankcase ventilation module (PCV / air-oil separator) uses an internal diaphragm that hardens and tears. When it does, the engine pulls unmetered air through the crankcase, gives up its ability to control crankcase pressure, and starts drawing oil into the intake. Owners typically see it between roughly 60,000 and 80,000 miles. Symptoms overlap with several other faults, which is why it is so often misdiagnosed - the tell is a rough or hunting idle combined with rising oil consumption and lean/crankcase-ventilation fault codes. Excess crankcase pressure also pushes oil past the rear main and cam seals, so a neglected PCV can create leaks that look like a much bigger problem.

This issue also affects: Audi A4, Audi A5, Audi A7

Common Symptoms

  • Rough, hunting or unstable idle
  • Increased oil consumption with no visible external leak
  • Blue smoke on startup or under load
  • Whistling or hissing from the top of the engine
  • Oil smell in the engine bay; oil pushed past cam or rear main seals

How to Fix

No recall. Replace the PCV / air-oil separator module with the current revised part number (Audi went through several revisions) along with its gaskets; the supercharger does not need to come off on all variants but access is tight. A smoke test or a crankcase-vacuum measurement at the oil filler confirms the diagnosis before parts are thrown at it. Replacing seals that were pushed out by crankcase pressure without fixing the PCV guarantees the leak returns.

Typical repair cost:$300 - $900

Research This Issue

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Community Reported
High ConfidenceVerifiedReviewed Aug 2026

On the 2010-2016 Audi S4, the B8/B8.5 S4's 3.0 TFSI is direct-injected: fuel is sprayed into the cylinder rather than over the back of the intake valve, so nothing washes the valve stems clean. Combined with oil vapor routed back through the crankcase ventilation system, hard carbon accumulates on the intake valves and ports, choking airflow. Symptoms come on gradually - a slow loss of throttle response and power, rougher cold idle, and cold-start misfires - which is why many owners never notice until the engine is cleaned. Owners commonly plan the service around 70,000-80,000 miles. Note the generational distinction: this is a direct-injection consequence, and the later B9 EA839 3.0T combines direct with port injection, which substantially reduces (though does not eliminate) the problem.

This issue also affects: Audi S8, Audi A4, Audi A1

Common Symptoms

  • Gradual loss of power and throttle response
  • Rough or shaky cold idle
  • Cold-start misfires
  • Reduced fuel economy
  • Hesitation under light load

How to Fix

There is no chemical spray-in that reliably removes hardened deposits. The accepted fix is mechanical: remove the intake manifold, scrape the heavy deposits, and walnut-shell blast the valves and ports. Replace the intake manifold gaskets on reassembly. A failing PCV accelerates the buildup, so inspect and replace it at the same time. Plan the cleaning as scheduled maintenance rather than waiting for misfire codes.

Typical repair cost:$500 - $1,200

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Community Reported
High ConfidenceVerifiedReviewed Aug 2026
Community reported
107 owners

On the 2010-2025 Audi S4 3.0T, the plastic thermostat housing on the S4 3.0T is prone to cracking and leaking coolant. The housing sits at the rear of the engine making leaks hard to spot until coolant loss is significant.

This issue also affects: Audi A5, Audi Q7, Audi S5

Common Symptoms

  • Coolant loss without visible leak
  • Overheating warning
  • Sweet smell from engine bay
  • Coolant puddle under rear of engine
  • Temperature gauge fluctuation
  • Low coolant warning

How to Fix

Replace thermostat housing assembly with updated part. Use OEM or quality aftermarket housing with metal reinforcement.

What you need to fix it

Only diagnosis- and fitment-reviewed repair parts are linked here.

  • Engine Coolant Thermostat Housing Assembly
    Cross-refTHRVG-0013

    Fitment confirmed against the ShowMeTheParts catalog for this vehicle's year and engine.

    eBay

As an Amazon Associate, we earn from qualifying purchases; other part links may also earn au7o a commission. Confirm fitment by VIN before buying.

Typical repair cost:$300 - $800

Research This Issue

Based on 107 owner reports

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Community Reported
High Confidence107 owner reportsLast reported by owners Mar 2026Reviewed Mar 2026
NHTSA Recalls5 recalls

EQUIPMENT:ELECTRICAL:INFOTAINMENT:VIDEO (TOUCH)SCREEN/MONITOR/UNIT

Volkswagen Group of America, Inc. (Audi) is recalling certain 2021-2022 AUDI A8, A6 Allroad, E-TRON Quattro, 2022 S3, RSQ8, RS7, RS6 Avant, Q8, Q7, Q3, E-TRON Sportback Quattro, S5 Cabriolet, E-TRON GT, S5 Sportback, A7, A6, A5 Sportback, A5 Cabriolet, A4, A4 Allroad, A3, S8, SQ7, SQ8, S6, and S4 vehicles. The infotainment main unit may become damaged internally when the vehicle is shut off, resulting in an inoperative rearview camera display the next time the vehicle is started. As such, these vehicles fail to comply with the requirements of Federal Motor Vehicle Safety Standard number 111, "Rear Visibility."

Campaign #22V80600026/10/2022

SEAT BELTS:REAR/OTHER:RETRACTOR

Volkswagen Group of America, Inc. (Volkswagen) is recalling certain 2021 Volkswagen ID4, Audi A4 Allroad, A4 Sedan, A5 Cabriolet, A5 Coupe, A5 Sportback, A6 Allroad, A6 Sedan, A7, A8, E-Tron Quattro, E-Tron Sportback Quattro, Q3, Q5, Q5 Sportback, Q7, Q8, RS5 Sportback, RS5 Coupe, RS6 Avant, RS7, RSQ8, S4 Sedan, S5 Cabriolet, S5 Coupe, S5 Sportback, S6 Sedan, S7, S8, SQ5, SQ5 Sportback, SQ7, SQ8, and 2021-2022 S3 Sedan vehicles. The rear seat belt automatic locking retractors may deactivate early, which can prevent the child restraint system from securing properly. As such, these vehicles fail to comply with the requirements of Federal Motor Vehicle Safety Standard number 208, "Occupant Crash Protection."

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Frequently Asked Questions

What are the most common Audi S4 problems?

According to Au7o's analysis of 107+ owner reports, the 2011 Audi S4 has 6 documented issues. The most frequently reported are: Fuel Rail or Seal Leak Creates Fire Risk (Recall 15V019 / 24AP), 0B5 DL501 S tronic Mechatronic Unit Failure - Harsh Shifts, Erratic Gear Selection and Limp Mode, Thermostat Housing Failure and Coolant Leak. Of these, 2 are rated critical and should be addressed promptly.

Is the Audi S4 reliable?

The 2011 Audi S4 has 6 known issues documented across 107+ owner reports. 2 issues are rated critical: Fuel Rail or Seal Leak Creates Fire Risk (Recall 15V019 / 24AP) and 0B5 DL501 S tronic Mechatronic Unit Failure - Harsh Shifts, Erratic Gear Selection and Limp Mode. Prospective buyers should inspect for these issues and factor potential repair costs into their purchase decision. Regular maintenance following the manufacturer's schedule helps prevent many common problems.

How much does it cost to fix common Audi S4 problems?

Repair costs for known Audi S4 issues range from $300 to $7,000, depending on the specific problem and whether you choose DIY or professional repair. Au7o provides step-by-step DIY maintenance guides that can help reduce repair costs.

What is the 2011-2012 Audi S4 Fuel Rail or Seal Leak Creates Fire Risk (Recall 15V019 / 24AP)?

Certain 2011-2012 S4 fuel-injection systems can leak at the fuel rails or corresponding seals, creating a fire risk near an ignition source. Severity: high.

What is the 2010-2016 Audi S4 0B5 DL501 S tronic Mechatronic Unit Failure - Harsh Shifts, Erratic Gear Selection and Limp Mode?

S4s ordered with the 7-speed S tronic dual-clutch use the 0B5 (DL501) gearbox, whose mechatronic control unit - the valve body with its integrated solenoids, pressure sensors and TCU - is a documented weak point in high-torque applications like the S4. Failures start as harsh or… Repairs typically run $1,800-$7,000. Severity: high.

What is the 2010-2025 Audi S4 Thermostat Housing Failure and Coolant Leak?

Content on this page was compiled with AI assistance using NHTSA complaints, TSBs, owner reports, and public automotive data. While we strive for accuracy, this information may contain errors. Always verify repair procedures and specifications with your vehicle's service manual or a qualified mechanic.

Data sourced from 107+ owner reports, NHTSA recalls, TSBs, and automotive forums.

Recalls
5
  • FAQ
  • Campaign #21V606000
    05/08/2021

    TIRES

    Volkswagen Group of America, Inc. (Audi) is recalling certain 2019-2021 Audi A5 Sportback, RS5 Coupe, RS5 Sportback, S5 Sportback, 2020-2021 A4 Allroad, A4 Sedan, A5 Cabriolet, A5 Coupe, A6 Allroad, A6 Sedan, A7, A8, Q5, S4 Sedan, S5 Coupe, S5 Cabriolet, S6 Sedan, S7, S8, SQ5, 2021 Q5 Sportback, Q7, Q8, RS6 Avant, RS7, RSQ8, SQ5 Sportback, SQ7, and SQ8 vehicles. The rear axle alignment may not have been inspected after the repairs for Recall 21V-295 (42L1) were performed.

    Campaign #22V03400026/01/2022

    SUSPENSION:REAR:AXLE:NON-POWERED AXLE ASSEMBLY

    Volkswagen Group of America, Inc. (Audi) is recalling certain 2021 Q7, Q8, Q5 Sportback, SQ5 Sportback, RS6 Avant, RS7, RS Q8, 2020-2021 Audi S6 sedan, Q5, A8, S8, A7, A6 Allroad, A5 Cabriolet, A4 sedan, A4 Allroad, SQ5, S7, A6 sedan, S5 coupe, S4 sedan, S5 Cabriolet, A5 coupe, 2019-2021 RS5 coupe, A5 Sportback, S5 Sportback, RS5 Sportback vehicles. The lock nut on the trailing arm of the rear axle may break due to stress corrosion.

    Campaign #21V29500026/04/2021

    BACK OVER PREVENTION:DISPLAY FUNCTION

    Volkswagen Group of America, Inc. (Volkswagen) is recalling certain 2021 Audi A8, RS7, RS6 Avant, RS5 Sportback, RS5 Coupe, Q8, Q7, Q5 Sportback, S4 Sedan, Q5, A7, A6, A6 Allroad, A5 Sportback, A5 Coupe, A5 Cabrioleet, A4 Sedan, A4 Allroad, E-Tron Sportback Quattro, SQ7, S5 Cabriolet, E-Tron Quattro, SQ8, SQ5 Sportback, SQ5, S8, S7, S6 Sedan, S5 Sportback, S5 Coupe, 2022 E-Tron GT, and 2021-2022 RSQ8 vehicles. Due to a software issue, a blank or black screen may be displayed instead of the rearview camera image when the vehicle is placed in reverse gear. As such, these vehicles fail to comply with the requirements of Federal Motor Vehicle Safety Standard number 111, "Rear Visibility."

    Campaign #22V74200005/10/2022

    Enter your VIN at NHTSA.gov to check recalls specific to your vehicle.

    The plastic thermostat housing on the S4 3.0T is prone to cracking and leaking coolant. The housing sits at the rear of the engine making leaks hard to spot until coolant loss is significant. Repairs typically run $300-$800. Severity: medium.

    What is the 2010-2016 Audi S4 Supercharger Coupler (Isolator) Wears Out and Rattles Like a Bag of Marbles?

    The B8/B8.5 S4's Eaton TVS roots supercharger drives its rotor pack through a plastic coupler disc between the drive snout and the driven rotor. Over time the drive holes in that plastic coupler elongate and wear, and the slop shows up as a distinct rattling / marbles-in-a-can no… Repairs typically run $400-$1,500. Severity: medium.

    What is the 2010-2016 Audi S4 3.0 TFSI PCV / Air-Oil Separator Diaphragm Ruptures, Causing Oil Consumption and a Crankcase Vacuum Leak?

    The supercharged 3.0 TFSI's crankcase ventilation module (PCV / air-oil separator) uses an internal diaphragm that hardens and tears. When it does, the engine pulls unmetered air through the crankcase, gives up its ability to control crankcase pressure, and starts drawing oil int… Repairs typically run $300-$900. Severity: medium.

    What is the 2010-2016 Audi S4 Carbon Deposits Build Up on the Intake Valves of the Direct-Injected 3.0 TFSI?

    The B8/B8.5 S4's 3.0 TFSI is direct-injected: fuel is sprayed into the cylinder rather than over the back of the intake valve, so nothing washes the valve stems clean. Combined with oil vapor routed back through the crankcase ventilation system, hard carbon accumulates on the int… Repairs typically run $500-$1,200. Severity: medium.