Audi Q8 loss of power problems

Filed Nov 3, 2026 · Engine, Fuel system · GA

I am reporting a serious and recurring safety issue involving my 2019 Audi Q8. The vehicle has experienced repeated engine system malfunctions that have ultimately resulted in complete engine shutdown while driving. The first incident occurred when the vehicle would not start and displayed an “Engine System Malfunction” warning. I was able to get the vehicle operational and bring it to the dealership, where the fuel pump was replaced. Just three days after the repair, the same problem returned, requiring the vehicle to be towed back to the dealership. The dealership cleared the diagnostic code and kept the vehicle for approximately three weeks before returning it to me, stating that the issue had been resolved. A few days after receiving the vehicle back, the malfunction occurred again. This time, the engine completely shut off while I was driving at highway speeds. This created an extremely dangerous situation, as the sudden loss of engine power at highway speeds presents a significant risk of a crash, particularly in traffic or while attempting to maneuver out of danger. The vehicle is currently completely inoperable, and the underlying issue remains unresolved despite multiple dealership visits and attempted repairs. I am concerned that this recurring malfunction represents a significant safety defect that could affect other Audi Q8 owners. The possibility of an engine unexpectedly shutting down while traveling at highway speeds presents an unacceptable safety risk. I am requesting that this complaint be documented and investigated to determine the underlying cause and whether other vehicles may be affected.

Filed Aug 22, 2026 · Engine · FL

I am reporting an ongoing cooling-system/water-pump issue with my 2020 Audi Q8, approximately 75,000 miles. The problem began when the vehicle repeatedly displayed a low-coolant warning. Inspection confirmed the coolant level was very low and a significant problem involving the coolant pump/vacuum system was diagnosed. The water pump was subsequently replaced. After the repair, the vehicle initially appeared normal, but problems continued. I experienced engine sputtering/rough running and the vehicle felt as though it might stall while stopped at a traffic light. A Drive System Malfunction/check-engine warning appeared, and cruise control/driver-assistance functions became unavailable. The check-engine light has continued to return intermittently. There was also an issue with a loose cap following the water-pump repair, which was corrected. Despite this, the low-coolant warning later returned and the coolant reservoir was again confirmed to be low. Coolant was added and the vehicle was returned to the repair facility to locate a leak. The shop kept the vehicle for several days and ran it for approximately two hours while inspecting it but could not reproduce or locate a coolant leak. The check-engine light went out during testing but returned shortly after the vehicle was picked up and driven normally. A sensor was also replaced based on a diagnostic code, but the check-engine light returned afterward. I have now spent more than $3,000 attempting to correct these issues, yet the cause of the recurring coolant loss and warning lights has not been determined. I am concerned that this may represent a recurring defect involving the water pump/cooling or related vacuum-control system. My primary safety concern is the possibility of unexpected coolant loss, overheating, engine malfunction, reduced power, or stalling while driving. I am requesting that this complaint be documented and investigated for similar incidents involving 2020 Audi Q8 vehicles.

Filed Jul 14, 2026 · Engine · CA

On July 4, 2026 in the early evening, I was driving in the HOV lane of the freeway when the engine abruptly lost power. There was a warning light that came onto the dashboard but I did not see what it said as I was solely concerned about moving safely off to the shoulder in moderate traffic. Once I pulled to the shoulder, I restarted the vehicle and was able to drive home safely. What put my wife and I in great danger was the vehicle losing power without warning when driving on the freeway and having to navigate safely to the shoulder in traffic without having acceleration power. I took the vehicle into the Audi Ontario dealer on July 6 for a rearview camera recall notice and to address the engine problem. I did not drive the vehicle after the July 4 incident but the loss of power did not happen again after I restarted the engine nor when I drove it to the dealer on July 6. The dealer notified me the next day that they could not recreate the engine problem and that the engine automatically turns off after coming to a stop. I explained I had not come to a stop, that I was driving at about 80 MPH with both hands on the steering wheel. I asked about what trouble codes they found and if I could have a print out since this was a safety concern and the vehicle only has 1,500 miles on it. The loss of propulsion was not the auto turn off when coming to a stop. They kept the vehicle for further review and I have not heard back as of July 14. I called to make inquiry and they are supposed to call me back. My concern is not only for me, but also for anyone that has this vehicle year, make, and model - the next person may not be so lucky to navigate to safety if it happens to them.

Filed Apr 30, 2026 · Engine · FL

I own a 2019 Audi Q8. The vehicle was in the dealership’s possession for approximately three (3) weeks for service. During that time, I was not informed of any significant mechanical concerns or issues. After retrieving the vehicle, it displayed an oil pressure warning while in operation. I immediately returned the vehicle to the dealership for evaluation. At that time, the dealership added oil (“topped off” the vehicle) and released it back to me without identifying or addressing the underlying cause of the warning. Following this, I made multiple attempts to have the vehicle properly diagnosed. I experienced difficulty obtaining assistance, including calls being disconnected, and I was not provided meaningful support or a thorough evaluation of the issue. Shortly after leaving the dealership, the vehicle began producing abnormal knocking noises and rapidly became unsafe to operate, requiring it to be towed. This situation presents a significant safety concern, as a sudden loss of power or drivability while driving can increase the risk of an accident, particularly in traffic conditions where maintaining speed is necessary. The condition has since been confirmed by a service provider as a major mechanical failure. Additionally, I have received documentation from the manufacturer indicating a known issue related to piston skirt defects associated with this vehicle. Despite the vehicle being in the dealership’s possession for an extended period, this issue was not identified, diagnosed, or addressed. I was also not provided clear assistance or guidance regarding potential warranty consideration related to this known issue. The vehicle is currently available for inspection upon request.

Filed Jan 30, 2026 · Transmission · SC

Audi Q8 failed water pump leading to severe loss of power and a major safety issue. I was merging on a very busy highway when I had loss of power with my children in the vehicle. This was alarming as I was not able to accelerate as anticipated and had no warning/notice that this was going to occur, and others around me did not know what was going on as well. This is a known complaint and issue in these vehicles and a major safety issue. Audi should stand behind their quality and it is dissapointing costly repair that shouldn’t be needed at 50 k (right outside of warranty). This issue can cause a detrimental accident.

Filed Jan 19, 2026 · Engine · FL

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.

Filed Sep 30, 2025 · IL

Faulty water pump → allowed coolant to migrate into the vacuum lines (a place coolant should never be). •This led to turbo underboost faults (loss of power) even though the turbo itself is fine. •The contaminated vacuum system now requires replacement of the vacuum shut-off valve and possibly other vacuum components. •Because of how the parts are placed, the repair requires removing the front bumper, and once it’s reinstalled, the safety systems/sensors must be recalibrated.

Filed Sep 15, 2025 · Fuel system · 60,000 miles · FL

The contact owns a 2021 Audi Q8. The contact stated that while driving at various speeds, the instrument panel failed to operate. The contact stated that while driving 70 MPH, the failure recurred. The contact received notification of the federal safety agency Campaign Number: 25V201000 (Electrical System), and the vehicle was taken to the dealer, where the recall repair was performed; however, the failure recurred the same day while driving from the dealer. Additionally, the contact stated that the vehicle stalled while driving at various speeds. The vehicle was taken to the dealer, where it was diagnosed that the fuel pump had failed, but the vehicle was not repaired due to the cost. The contact stated that while driving 50-55 MPH, the messages "Loss of Power", "Reduced RPMs to 3,000", and other unknown messages were displayed, and the vehicle stalled. The vehicle was towed to the residence. The contact related the failure to the federal safety agency Campaign Number: 22V516000 (Fuel System, Gasoline); however, the VIN was not included. The vehicle was not repaired. The manufacturer was notified of the failures. The failure mileage was approximately 60,000.

Filed Apr 22, 2025 · Driver assistance, Electrical · CO

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.

Filed Feb 20, 2025 · Engine · NC

- The water pump failed, leading to a coolant leak and potential engine overheating. The failed component is not available for inspection, as it was replaced by an independent repair shop after the dealership quoted an excessive price and could not complete the repair in a timely manner. - A failing water pump can cause engine overheating, sudden power loss, or complete engine failure while driving, which increases the risk of an accident. Additionally, I noticed the smell of coolant inside the cabin, which could indicate a leak that might pose a fire hazard or expose occupants to coolant fumes. - Yes, the issue was diagnosed by an Audi dealership (Audi Northlake), which confirmed that the water pump had failed and needed replacement. Due to their high repair quote and scheduling delays, I had the repair completed at an independent service center, which also confirmed the failure and replaced the water pump. - The issue was confirmed by an Audi dealership but was not formally inspected by Audi corporate, law enforcement, or an insurance company. - Yes, I noticed a coolant smell inside the cabin for a few days before taking it to the dealership. However, there were no warning lights or messages on the dashboard before the failure was diagnosed.