2021 Audi Q7: engine stalls while driving

Filed Dec 15, 2025 · Engine · GA

- Engine water pump failure and coolant intrusion into the vacuum system. Parts were replaced on 5 Nov 2025 and possible still at the dealer's location. - The defect poses the following safety risks: It resulted in contamination of vacuum lines; potential for sudden engine stalling or loss of power while driving; potential for catastrophic damage to engine-management systems dependent on vacuum integrity; potential for damage to emissions and combustion-control systems; potential for reduced braking system performance if vacuum supply is compromised, expensive and unexpected component failures, and possible recurrence since the cause appears related to design rather than normal wear. Any failure can create cascading hazards affecting safety-critical functions. - The problem was confirmed by an authorized Audi dealer. Dealer name and contact info can be provided upon request. - I do not know if the dealer delivered the involved parts to the manufacturer or insurance representative for inspection. Police or others did not inspect it. - There were no warning lights, messages, or other symptoms of the problem prior to the failure. It was identified by the Audi technician on 5 November 2025 while the vehicle was in the dealer for other services. The failure occurred at 47,855 miles which is far below the average lifespan of a water pump or vacuum system.

Filed Nov 17, 2025 · Electrical · NY

I am filing this complaint regarding a serious safety and mechanical issue involving my 2021 Audi Q7. The alternator on my vehicle was replaced by Audi in November 2024 as part of an official Audi recall. On October 22, 2025, less than one year later, the alternator failed while I was driving, causing the following safety hazards and damages: Sudden loss of battery power Complete battery drain Damage to the electrical stabilizer Vehicle shut down while driving Required towing Left me stranded on the road Another independent auto shop confirmed that the alternator failure directly caused the battery to fail. My vehicle is only four years old, and the battery should not fail under normal operation unless another component (such as the alternator) is defective. Audi of America refuses to cover the resulting damages, even though the alternator was replaced under their recall and failed prematurely. They have denied reimbursement for repairs, towing, and related expenses, despite clear evidence that the alternator caused the battery and electrical damage. This is a serious safety concern because the alternator failed without warning, and the vehicle lost electrical power while driving. I am requesting the federal safety agency to review this issue, as the failure of the recall-installed alternator may impact other Audi Q7 owners and may indicate a broader defect or improper recall repair. Thank you for your attention to this matter

Filed May 27, 2025 · Brakes, Electrical · NJ

I am reporting a severe defect in my 2020 Audi Q7 involving “coolant migration” due to a faulty water pump, a known issue in Audi models (Q7, S4, A6, 2013–2022). This poses critical safety risks due to sudden failure with minimal warning. My out-of-warranty Q7 showed minor coolant fouling near a solenoid, with normal coolant levels and no fluid added. The dealer quoted ~$6,000 to replace the water pump and vacuum system. This defect is highly dangerous due to: Sudden Power Loss: Coolant in the vacuum system impairs solenoids and lines, disrupting engine/turbo function. This can cause abrupt power loss, risking loss of control in traffic or at high speeds, potentially leading to collisions. Catastrophic Overheating: A failing water pump may halt coolant circulation, causing rapid engine overheating without warning, risking sudden engine shutdown and stranding drivers in hazardous conditions like highways. Brake Assist Failure: The vacuum system powers the brake booster. Contamination can reduce braking effectiveness, increasing pedal effort and stopping distances, heightening collision risks in emergencies. Emissions Control Issues: Coolant fouling affects PCV and EVAP systems, causing misfires, stalling, or increased emissions, potentially triggering check engine lights and compromising engine stability. Undetectable Progression: The defect often shows no clear symptoms or warnings until severe damage occurs. My vehicle had only minor fouling that could only be detected by visual inspection, yet extensive repairs were needed, indicating the issue’s stealthy nature, which prevents timely driver intervention. Systemic Issue: Forums and a class-action lawsuit confirm this defect across Audi models, yet owners face high repair costs post-warranty. This defect endangers drivers and others by risking vehicle failure, impaired braking, and unstable performance. I urge the federal safety agency to investigate and mandate a recall or extended warranty.

Filed Nov 15, 2024 · Electrical, Engine · PA

Driving on highway at 70 mph and high engine temp light came on. Said to pull over and continue to run car until temp decreased. I got over as quickly as I could ( no more than 1/4 of a mile) and sat on side of PA turnpike as engine cooled. I was at bottom of an exit ramp. I slowly proceeded up the ramp and warning came on again and red temp light reached again. I pulled right into the gas station at top of TP exit ramp. It still said to continue to run the car. I sat with my son in the car and ran the car in the shade. The temp was decreasing and then all my electrical lights came on, yellow battery warning light on and then suddenly the red battery light and all systems failed. Car turned off. Called AAA to take to my mechanic as Audi was a 3 hour wait for a tow and 3 weeks for service appointment with no loaners available. My certified mechanic said water pump completely dislodged. He replaced water pump, thermostat (which was already replaced bc it failed in year 2 of ownership). After repair, 48 volt battery would not take a charge. Assumed faulty alternator and/or battery. Alternator was already replaced once at year 1 as car died while driving as well. We had car towed to audi and they are reporting known issues with water pump but not issuing recalls. Also known issues with alternator repair parts that were used in year 1 but no warning to consumers. They are diagnosing problem now and if alternator and subsequent battery issue, it will be covered but not if battery issue comes back as electrical in nature.

Filed Aug 16, 2023 · 26,789 miles · TX · 1 injury

The contact owns a 2021 Audi Q7. The contact stated that while driving at unknown speeds and making a left turn, the vehicle jerked and stalled. The contact was able to pull over into a parking lot. There was an unknown red message displayed regarding the pressure sensor. The driver sustained injuries to the head, arm, neck, and back, but medical attention was not provided. The contact called the local dealer, but the vehicle was not diagnosed or repaired. The manufacturer was not contacted. The failure mileage was approximately 26,789. The VIN was not available.