What 28 owners told NHTSA about the 2021 Audi Q8

I was driving my car would not accelerate on the highway and it almost caused me to get into an accident with my niece in the car. When I took the car to Audi this is what I was told my the service adviser. “Good afternoon. The technician has been looking into the vehicle and has found the cause of the issue. He has found the coolant water pump has failed internally causing coolant to leak internally into the vacuum system. This is causing the vacuum to be blocked for the turbo and thus causing the sluggish feeling when accelerating. In order to fix, the water pump and all compromised vacuum system components need to be replaced. It is a rather extensive job unfortunately.” My car only has a little over 45 thousand miles. Audi should be responsible to fix this problem because they sold this car knowing the water was faulty in these models. I recall should have been put out. I was quoted $6,000 to fix this problem.

NHTSA ODI 11741357

The engine (internal mechanical failure) malfunctioned. The vehicle developed a persistent ticking/knocking noise from the engine bay, and the authorized Audi dealer diagnosed the issue as requiring a full engine replacement. The vehicle is currently available for inspection upon request. A catastrophic engine failure presents a risk of sudden loss of power, stalling, or engine seizure, which could occur while driving at speed or in traffic. This creates a potential risk of loss of vehicle control, inability to accelerate, or being stranded in unsafe conditions, endangering both the driver and other motorists. The problem was confirmed by an authorized Audi dealership, which diagnosed the vehicle and stated that a complete engine replacement is required. The estimated repair cost provided by the dealer is approximately $26,000 (so far in parts only). The vehicle has been inspected and diagnosed by an authorized Audi dealership. At this time, it has not been inspected by police or insurance representatives. Audi corporate has been contacted for review. The primary symptom was a persistent ticking noise from the engine bay, which began around late December 2025 / early January 2026. There were no immediate warning lights or dashboard messages at the onset of the noise. The noise progressively worsened, prompting dealer inspection and diagnosis.

NHTSA ODI 11711800

On April 2, 2025, while driving on Interstate 25, my 2021 Audi Q8 Premium Plus experienced a catastrophic engine and electrical failure. This included the generator system failing, which resulted in a complete loss of power, disabling all active safety systems (including electronic stability control, braking assist, and lane monitoring), as well as basic driving capabilities such as acceleration and steering responsiveness. The incident occurred without prior warning or diagnostic alerts, and the vehicle became immobile on the highway. The situation posed a serious safety hazard to both myself and surrounding drivers. The vehicle had an unresolved generator recall, which Audi later confirmed and completed after the incident. This event raises significant concerns regarding system reliability and pre-failure alert mechanisms in the Q8 platform.

NHTSA ODI 11656169

I wish to report a critical safety issue with our Audi Q8, which experienced a complete electrical failure while traveling at 65 mph on the freeway on [XXX]. The warning indicators transitioned from yellow to red before the vehicle lost all functionality, including turn signals and emergency blinkers, posing a severe risk to my family and other motorists. We managed to coast to the roadside without incident, but the potential for a catastrophic outcome was alarmingly high. Audi has identified the problem as an alternator defect, which is apparently a known issue covered under an extended warranty for Audi Q8 2019-2022 for 7 years unlimited miles. However, the policy to address this defect only upon failure is unacceptable and dangerous. This malfunction could reoccur at any time, significantly endangering everyone on the road. Importantly, we frequently tow an Airstream trailer with our Q8. Had this failure occurred while towing, the consequences could have been disastrous on a large scale, endangering not only our family but also other road users due to the increased risk of a multi-vehicle collision, tipping over of Airstream or the Q8 if hit by vehicle who didn’t The replacement part's minimum of 3-8+ weeks wait time exacerbates our concern, leaving us without a vehicle or ability to use our Airstream which is one reason why we purchased the Audi Q8. I am aware of similar incidents of this failure in SF Bay Area across the past 4-6 months, underscores the need for immediate investigation and action to prevent future occurrences. We frequently travel on challenging routes like [XXX] in California as we own a home in Santa Cruz highlight the urgent need for a reliable vehicle. The thought of such a failure under those circumstances on a routine drive home or while towing, is unthinkable but could have happened to us at anytime. We urge the NHTSA to investigate this matter thoroughly to ensure the safety of all Q8 drivers public. Sincerely, [XXX] INFORMATION REDACTED PURSUANT TO THE FREEDOM OF INFORMATION ACT (FOIA), 5 U.S.C. 552(B)(6)

NHTSA ODI 11576760

Complete loss of electrical power while driving due to faulty alternator at only 35K miles. This resulted in total loss of steering, suspension failure, and any other electrical systems in the car. Making the car almost impossible to control specially for a new driver. Apparently the issue is widespread with any Audi car or SUV equipped with a V6 3 liter engine. The repair requires the replacement of the alternator and the 12v (an in some cases 48v) battery. The issue happens suddenly with no prior warning and completely disables the vehicle while driving. To the best of my knowledge Audi replaces the alternator with the same faulty design, which may lead to the issue to appear again at a later time.

NHTSA ODI 11547234

The contact owns a 2021 Audi Q8. The contact stated while driving 70 MPH, the vehicle shutoff as the electrical problem, see local dealer warning message appeared on the instrument panel. The contact pulled off to the side of the highway and had the vehicle towed to a local dealer. The vehicle remained in the possession of the dealer and had yet to be diagnosed. The manufacturer had yet to be notified of the failure. The vehicle had yet to be repaired. The failure mileage was approximately 3,500.

NHTSA ODI 11432422