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Audi · Known Issues

2017 Audi A4 Problems: 3 Known Issues

2017 model year · 1,900+ owner reports · Updated September 2026

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Issue summary

According to Au7o's analysis of 1,900+ owner reports, the 2017 Audi A4 has 3 documented known issues, with 1 rated critical. The most serious is S-Tronic (DSG) Mechatronic Unit Issues ($600-$4,000 repair). The most commonly reported issue is S-Tronic (DSG) Mechatronic Unit Issues with 980 owner reports. Across all issues with published estimates, repair costs range from $150 to $4,000. DIY maintenance guides at au7o.io.

In This Article

  • A4 Transmission1
  • A4 Cooling1
  • A4 Fuel System1
  • Recalls5
  • FAQ
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In This Article

  • Transmission1
  • Cooling1
  • Fuel System1
  • Recalls5
  • FAQ

All 3 Known Issues

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Community reported
980 owners

On the 2009-2020 Audi A4, the S-Tronic dual-clutch transmission can experience mechatronic unit problems, similar to VW's DSG issues. This can cause shifting problems, jerky operation, and warning lights.

This issue also affects: Audi A3, Audi A5, Audi R8

Common Symptoms

  • Harsh or jerky shifts
  • Transmission warning light
  • Stuck in gear (limp mode)
  • Shuddering at low speeds
  • Delayed engagement

How to Fix

S-Tronic fluid change every 40,000 miles is critical. Mechatronic unit replacement if failed. Some issues resolved with software updates. Regular fluid maintenance extends life significantly.

Typical repair cost:$600 - $4,000

Research This Issue

Based on 980 owner reports

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Community Reported
High Confidence980 owner reportsLast reported by owners Feb 2023Reviewed Feb 2026
Community reported
920 owners

On the 2009-2018 Audi A4 2.0T, various plastic coolant flanges and fittings can crack and leak, particularly on the side of the engine. These plastic components become brittle with age and heat exposure. Multiple leak points possible.

This issue also affects: Audi A5, Audi Q3, Audi Q5

Common Symptoms

  • Coolant leak on side of engine
  • Low coolant warning
  • Sweet coolant smell
  • Overheating if severe
  • Coolant puddle after parking

How to Fix

Replace failed coolant flange or fitting. Consider replacing nearby plastic fittings while in there as they likely have similar wear. Metal replacement flanges available from aftermarket.

Typical repair cost:$150 - $500

Research This Issue

Based on 920 owner reports

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Community Reported
High Confidence920 owner reportsLast reported by owners Jan 2023Reviewed Feb 2026

On the 2009-2021 Audi A4, audi states that contaminated gasoline or gasoline with insufficient deposit-control additives can contribute to deposits on intake valves, the intake manifold, fuel injectors and combustion chambers. Possible results include rough running after cold start, extended cranking, hesitation, rough idle, reduced performance, poor fuel economy or an MIL with supported misfire, lean-system or cylinder-imbalance faults. This does not establish a universal A4 2.0T intake-valve defect, mandatory walnut-blasting interval or fixed failure mileage.

This issue also affects: Audi S8, Audi A1, Audi A5

Common Symptoms

  • Rough running after a cold start
  • Excessive engine cranking time
  • Hesitation while driving
  • Rough idle
  • Reduced engine performance
  • Poor fuel economy
  • MIL with supported misfire, lean-system or cylinder-imbalance faults

How to Fix

Confirm that the vehicle is gasoline-powered, document fuel quality, symptoms and stored DTCs, and follow current guided diagnosis before cleaning or replacing anything. If contaminated gasoline is suspected, change fuel source; if detergent quality is suspect, Audi recommends Top Tier detergent gasoline. Identify the actual deposit location before selecting a cleaning process. Do not prescribe routine walnut blasting, a catch can, chemical cleaner or high-RPM driving from this record.

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Manually Verified
High ConfidenceVerifiedReviewed Jul 2026
NHTSA Recalls5 recalls

SEATS

Volkswagen Group of America, Inc. (Audi) is recalling certain 2017-2020 A4 Allroad, A4 Sedan, 2018-2019 RS5 Coupe, 2019 RS5 Sportback, 2018-2020 A5 Cabriolet, A5 Coupe, A5 Sportback, S4 Sedan, S5 Cabriolet, S5 Coupe, and Audi S5 Sportback vehicles. The cable connecting the seat heater to the Passenger Occupant Detection System (PODS) may have a contact fault, causing the software to misdiagnose a malfunction and disable the passenger air bag.

Campaign #21V87400010/11/2021

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
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Frequently Asked Questions

What are the most common Audi A4 problems?

According to Au7o's analysis of 1,900+ owner reports, the 2017 Audi A4 has 3 documented issues. The most frequently reported are: S-Tronic (DSG) Mechatronic Unit Issues, Coolant Flange/Fitting Leaks, 2009-2021 A4 2.0T Gasoline-Quality Deposit Diagnosis - TSB 2014753/13. Of these, 1 is rated critical and should be addressed promptly.

Is the Audi A4 reliable?

The 2017 Audi A4 has 3 known issues documented across 1,900+ owner reports. 1 issue is rated critical: S-Tronic (DSG) Mechatronic Unit Issues. 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 A4 problems?

Repair costs for known Audi A4 issues range from $150 to $4,000, depending on the specific problem and whether you choose DIY or professional repair. The most critical issue, S-Tronic (DSG) Mechatronic Unit Issues, typically costs $600-$4,000 to repair. Au7o provides step-by-step DIY maintenance guides that can help reduce repair costs.

What is the 2009-2020 Audi A4 S-Tronic (DSG) Mechatronic Unit Issues?

The S-Tronic dual-clutch transmission can experience mechatronic unit problems, similar to VW's DSG issues. This can cause shifting problems, jerky operation, and warning lights. Repairs typically run $600-$4,000. Severity: high.

What is the 2009-2018 Audi A4 Coolant Flange/Fitting Leaks?

Various plastic coolant flanges and fittings can crack and leak, particularly on the side of the engine. These plastic components become brittle with age and heat exposure. Multiple leak points possible. Repairs typically run $150-$500. Severity: medium.

What is the 2009-2021 Audi A4 2009-2021 A4 2.0T Gasoline-Quality Deposit Diagnosis - TSB 2014753/13?

Audi states that contaminated gasoline or gasoline with insufficient deposit-control additives can contribute to deposits on intake valves, the intake manifold, fuel injectors and combustion chambers. Possible results include rough running after cold start, extended cranking, hes… Severity: medium.

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 1,900+ owner reports, NHTSA recalls, TSBs, and automotive forums.

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.