2021 Audi S4 Problems: 3 Known Issues

2021 Audi S4 Problems: 3 Known Issues | Au7o

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."

Campaign #21V60600005/08/2021

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.

Frequently Asked Questions

What are the most common Audi S4 problems?

According to Au7o's analysis of 107+ owner reports, the 2021 Audi S4 has 3 documented issues. The most frequently reported are: EA839 3.0T Water Pump Internal Seal Failure Leaks Coolant Into the Vacuum System (Class Action), Rear Axle Trailing Arm Eccentric Bolt Lock Nut Can Break from Stress Corrosion (Recall 21V295 / 42L1), Thermostat Housing Failure and Coolant Leak. Of these, 2 are rated critical and should be addressed promptly.

Is the Audi S4 reliable?

The 2021 Audi S4 has 3 known issues documented across 107+ owner reports. 2 issues are rated critical: EA839 3.0T Water Pump Internal Seal Failure Leaks Coolant Into the Vacuum System (Class Action) and Rear Axle Trailing Arm Eccentric Bolt Lock Nut Can Break from Stress Corrosion (Recall 21V295 / 42L1). 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 $0 to $3,000, depending on the specific problem and whether you choose DIY or professional repair. The most critical issue, EA839 3.0T Water Pump Internal Seal Failure Leaks Coolant Into the Vacuum System (Class Action), typically costs $1,200-$3,000 to repair. Au7o provides step-by-step DIY maintenance guides that can help reduce repair costs.

What is the 2018-2025 Audi S4 EA839 3.0T Water Pump Internal Seal Failure Leaks Coolant Into the Vacuum System (Class Action)?

The B9 S4's turbocharged EA839 3.0T uses a water pump whose internal seals fail, and the failure mode is unusual: coolant does not only weep externally, it is drawn INTO the engine's vacuum circuit and other places coolant should never reach, contaminating vacuum lines and compon… Repairs typically run $1,200-$3,000. Severity: high.

What is the 2020-2021 Audi S4 Rear Axle Trailing Arm Eccentric Bolt Lock Nut Can Break from Stress Corrosion (Recall 21V295 / 42L1)?

Lock nuts from particular production batches used on the eccentric bolt at the rear-axle trailing arm can crack from stress corrosion. If the nut breaks, the eccentric bolt can move and the rear-axle wheel alignment changes - and at higher speed the rear axle can suddenly and unc… Repairs typically run $0-$0. Severity: high.

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

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.

2021 Audi S4 Problems: 3 Known Issues

All 3 Known Issues

2018-2025 Audi S4: EA839 3.0T Water Pump Internal Seal Failure Leaks Coolant Into the Vacuum System (Class Action)#

Common Symptoms

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2010-2025 Audi S4: Thermostat Housing Failure and Coolant Leak#

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2020-2021 Audi S4: Rear Axle Trailing Arm Eccentric Bolt Lock Nut Can Break from Stress Corrosion (Recall 21V295 / 42L1)#

Common Symptoms

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Other Audi Models

Frequently Asked Questions

What are the most common Audi S4 problems?

Is the Audi S4 reliable?

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

What is the 2018-2025 Audi S4 EA839 3.0T Water Pump Internal Seal Failure Leaks Coolant Into the Vacuum System (Class Action)?

What is the 2020-2021 Audi S4 Rear Axle Trailing Arm Eccentric Bolt Lock Nut Can Break from Stress Corrosion (Recall 21V295 / 42L1)?

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