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2021 Audi A6 Problems

Owner-reported complaints filed with NHTSA, grouped by component

Data refreshed

Owner complaintsComplaints are reports submitted to NHTSA by owners and drivers. NHTSA does not verify most reports before publishing them, and a complaint does not establish that a defect exists. Volume is influenced by how many of a vehicle were sold, how long it has been on the road, and how much attention an issue has received.
15
Latest May 15, 2026
Components namedHow many of our component categories appear on at least one report for this model year. One report can name several.
6
Crash or fire reportedComplaints whose submitter recorded that a crash or a fire occurred. These are the reporter's own answers on the NHTSA form, not verified findings.
0

What this page shows

Everything below is an owner-reported complaint submitted to NHTSA about the 2021 Audi A6, grouped by the component NHTSA recorded on the report. These are not confirmed defects, and they are not recalls. NHTSA does not verify most reports before publishing them, and a category with more reports in it is not evidence that a part is defective.

Complaints are reports submitted by owners and drivers to NHTSA. They are not verified and do not establish that a defect exists.

Reports by component

Ranked by how many owner reports name each component category

  • Engine316.7%
  • Driver assistance211.1%
  • Powertrain (other)211.1%
  • Body & structure15.6%
  • Steering15.6%

Percentages are of component mentions. A single complaint can name more than one component, so these do not sum to the total complaint count.

Each component in detail

What the reports in each category say, in the owners' own words

Electrical

Reports naming the electrical system — wiring, battery, charging, control modules, infotainment and electrical accessories.

9
reports

From owner reports, verbatim

My alternator was not working and it was a recall and I paid to fix it and they don’t wanna pay me back. I got a new part from audi and fix it at the shop and they don’t wanna pay anything just called and she said we don’t pay only if he’s done at the dealer. And I don’t believe that! Bc dealer told me they pay if I fix it any where to get done quick bc was out stock

NHTSA ID 11720235 · filed Feb 24, 2026

While driving at normal speed, the entire digital instrument panel suddenly went black and a red warning triangle appeared. I lost all gauges, including speedometer, fuel level, and warning indicators. This created a serious safety risk because I was in active traffic and had no way to know my speed or see alerts. My VIN shows an open recall for this exact defect (instrument cluster blackout), but the failure has already happened during normal driving. I consider the vehicle unsafe to drive until repaired.

NHTSA ID 11703548 · filed Dec 7, 2025
All 9 reports naming electrical

Engine

Reports naming the engine itself — including stalling, misfires, oil consumption, cooling and internal engine components.

3
reports

From owner reports, verbatim

The contact owns a 2021 Audi A6. The contact stated while driving at an undisclosed speed, the vehicle overheated. The engine overheating and the low coolant warning light illuminated. In addition, the engine seized. The vehicle was taken to the dealer where it was diagnosed with a coolant leak and a failed coolant pump vacuum. The contact was informed that the coolant pump vacuum assembly needed to be replaced. The vehicle was not repaired. In addition, the contact was informed that the failure was a known failure of the vehicle. The manufacturer was made aware of the failure and a case was filed. The contact was advised to contact the NHTSA Hotline and report the failure. The failure mileage was approximately 80,000.

NHTSA ID 11736958 · filed May 11, 2026

Thermostat housing and oil cooler bracket leaking coolant with only 56k miles on the car

NHTSA ID 11736875 · filed May 10, 2026

Too few reports in this category for a page of its own — they appear in the full complaint list.

Driver assistance

Reports naming forward-collision avoidance, lane keeping, back-over prevention, cruise control and related electronic driver-assistance systems.

2
reports

From owner reports, verbatim

The Audi Pre-sense is activated by weather. I was driving during a thunderstorm and Audi Presence activated causing the car to come to a hard stop due to precipitation. It happened again backing out of my driveway the Audi Pre-sense was activated and the car came to a hard stop. I thought I had back into another vehicle. This is very dangerous.

NHTSA ID 11680304 · filed Aug 13, 2025

The car has had multiple issues with warning lights and malfunctioning systems. Including : 1.Child locks 2.Every single component of the ADAS 3. Emergency services being activated at least a few times a month - this is an SOS for emergency 911 service. The repeated, continuous and mostly false warning lights are a driving distraction that can easily cause an accident. I have photos of all warning lights coming on in the vehicle. The dealership has repeated stated that they couldn't reproduce the problem even though pictures were provided and the car is still under the original warranty period. The latest attempt to fix the vehicle was to replace the sensors on the front of the vehicle. This solution was only attempted after the 4th report of the problem to the dealership where the car was serviced under the original manufacturers warranty

NHTSA ID 11638013 · filed Jan 23, 2025

Too few reports in this category for a page of its own — they appear in the full complaint list.

Powertrain (other)

Powertrain reports that are not specifically the engine or transmission — driveshafts, axles, transfer cases and differentials.

2
reports

From owner reports, verbatim

I was driving my vehicle when the engine surged and then a transmission warning light came on and there was an immediate and complete loss of drive power. After the vehicle glided to a stop, there was no drive transmission in either forward or reverse. There was no pre-warning and no earlier incidence that led up to this issue. The vehicle is five years old with 39,834 miles and has had all routine maintenance and mileage interval services performed at the dealership, including its recent (Dec-25) 40,000-mile service. Thankfully this complete failure occurred when I was in my neighborhood and travelling 20mph; otherwise, the results could have been catastrophic had it occurred on a multilane highway at speeds of 65-70 MPH. The vehicle was towed to Audi of Indianapolis where the issue was identified as one broken bolt and two loose bolts for the transmission filter cap. This matches a known Audi Issue with a Technical Service Bulletin issued December 13, 2024, where they acknowledge a complete loss of power and a root cause of broken/loose bolts in the transmission filter. This is a known issue and is happening on low mileage well serviced vehicles. Because this issue is known and could result in a severe accident and/or loss of life under high-speed multi-lane highway conditions, it seems Audi of America should issue a recall versus just a TSB and/or extend the warranty for this issue up to 10 years or 100,000 miles which would, perhaps, be considered a normal lifespan for a part.

NHTSA ID 11730290 · filed Apr 9, 2026

My alternator was not working and it was a recall and I paid to fix it and they don’t wanna pay me back. I got a new part from audi and fix it at the shop and they don’t wanna pay anything just called and she said we don’t pay only if he’s done at the dealer. And I don’t believe that! Bc dealer told me they pay if I fix it any where to get done quick bc was out stock

NHTSA ID 11720235 · filed Feb 24, 2026

Too few reports in this category for a page of its own — they appear in the full complaint list.

Body & structure

Reports naming the vehicle structure, frame, body panels, doors, hood and trim.

1
report

From owner reports, verbatim

Sunroof spontaneously shattered while driving. No other cars around when this occurred. Caused a very loud BANG. Was driving on the freeway when this occurred. Dealer would not confirm issue was spontaneous - felt something must have hit the car to cause this. No defined impact location on roof. Also, roof glass was pushed up in the middle instead of down like would be expected if something hit it from the outside. No warning before it occurred.

NHTSA ID 11485934 · filed Sep 22, 2022

Too few reports in this category for a page of its own — they appear in the full complaint list.

Steering

Reports naming the steering system — racks, columns, power-steering assist and steering linkage.

1
report

From owner reports, verbatim

Car reported an engine restarter issue (with battery symbol) and recommended to contact the dealer. Car next shut down automatic restart system, and air conditioning stopped working. Within a short period of time (same day), the car listed a red battery symbol and advised to stop the car. After doing so and contacting the Audi roadside, the car was listing a series of issues on multiple symptoms while also saying in the warning message "still okay to drive". These systems included steering, braking, and what seemed to be other sensors the car powers. Finally (and within 5 minutes of the previous message of being okay to drive), the warnings were continuous and started including the transmission. The car stopped accelerating (we were on the expressway) and we thankfully got to the side of the road. This was an enormously dangerous situation as the car became fully disabled and we were subject to limited options of relief from a major traffic area. Within 30 minutes of being disabled, no electrical charge was present in the car, including emergency flashers, making the situation more dangerous as it was nighttime, so we had to abandon the car and walk down the expressway to find a hotel. Could not even put the car in neutral for the tow. Service is initially reporting a failure of the restart generator. This appears to be an alarmingly common issue with Audis.

NHTSA ID 11543607 · filed Sep 9, 2023

Too few reports in this category for a page of its own — they appear in the full complaint list.

Higher-selling and older vehicles accumulate more reports. Counts are not failure rates and are not directly comparable between vehicles that sold in very different numbers.

Elsewhere on this vehicle

Data sources

Data on this page last refreshed .