Audi Q7 loss of power problems

Filed Oct 25, 2026 · Engine · NC

In XXX, my 2017 Audi Q7 3.0T unexpectedly lost engine power while traveling approximately 70 mph on a highway in [XXX]. A "Drive System Malfunction" warning appeared. The driver pulled over, shut off the engine, and restarted it; the vehicle then drove normally. The sudden reduction in power at highway speed created a risk of collision with surrounding traffic. The precise cause is UNKNOWN. I reported the highway-speed loss of power and warning to Audi Wilmington. At its XXX visit (102,255 miles), the dealership documented the warning and multiple engine misfire codes. It identified a vacuum leak at a broken oil-fill pipe neck, replaced the pipe, cleared codes, and reported no issue during its test drive. The intermittent power loss did not recur during that visit. The vehicle also had recurring excessive oil consumption. In XXX (104,261 miles), Audi Wilmington found it approximately 1.5 quarts low and documented possible piston-and-ring replacement if proposed treatments failed. Those proposed repairs were not performed. In XXX (approximately 109,320 miles), the vehicle again showed a Drive System Malfunction warning and check engine light. Maguire Audi documented multiple misfires and a persistent cylinder #2 misfire after service, and suspected internal engine damage. The vehicle has been out of service since then. Independent testing in XXX confirmed cylinder #2 had 35 PSI compression and 100% leak-down, with part of an exhaust valve missing and oil on the piston. The connection, if any, between the XXX power loss and later engine damage is UNKNOWN. Authorized Audi dealers and an independent shop have inspected the vehicle; I am unaware of any inspection by police, insurers, or the manufacturer. The vehicle remains in my possession and is available for inspection. INFORMATION REDACTED PURSUANT TO THE FREEDOM OF INFORMATION ACT (FOIA), 5 U.S.C. 552(B)(6)

Filed Oct 25, 2026 · Electrical · VA

COMPONENT: 48V mild-hybrid electrical system — engine ground connections, Belt Starter Generator circuit, and 48V lithium battery. The vehicle is available for inspection upon request; the 48V battery dealer now call failed has not yet been replaced. SAFETY RISK: On 8/1/2026, the vehicle suffered sudden, complete electrical failure while in motion immediately after exiting I-75 in Bradenton, FL, with my family aboard, including a child. The cluster displayed “Electrical system: malfunction! Safely stop vehicle” (red), then total power loss. I coasted into a parking lot; had this occurred minutes earlier at 70 mph in interstate traffic, a stall with degraded accessories would have been unavoidable. The vehicle would not restart until the system cooled. Risk is ongoing: faults now recur almost daily. CONFIRMED BY DEALER: Yes. Audi Sarasota (RO AUCS126809) diagnosed both main engine ground connections left loose after a 2/2026 engine replacement by an authorized Audi dealer — DTC U350100, Control Module Input Power “A” Circuit Low. A prior dealer had misdiagnosed it as a faulty 12V battery and returned the car unrepaired; it failed on the interstate 16 days later. In 10/2026 another dealer confirmed continuing failure (DTC P0A9400, DC/DC Converter Performance) and states the 48V battery is now failed, quoting $3,700 — probable consequential damage from the prolonged ground fault. OTHER INSPECTIONS: Three authorized Audi dealers; events also logged in Audi’s connected-vehicle telematics (manufacturer-accessible). Audi of America case 07647729 is open. PRIOR WARNINGS: Yes. Intermittent “Electrical system: malfunction” warnings began ~7/2026, escalating over weeks to persistent warnings and A/C loss (48V-powered) on 7/30/2026, two days before the failure. The same failure mode matches the BSG defect in the Steinhardt v. Volkswagen settlement

Filed Sep 15, 2026 · Engine, Fuel system · OK

I have heard a knocking and experienced sudden loss of power while driving- not electrical loss, but vehicle suddenly slows down and unable to pick back up speed effectively creating a safety concern when driving- especially at on ramps. A warning light comes on and then it will go off randomly with the loss of power. I have taken it in multiple times and was told it is an emissions issue and a vacuum hose issue that allows fluid to get into my turbos or something along those lines. I have both been told by my Audi service advisor and done my own research and seen there have been issues with previous years and ultimately a recall was done to fix those- My vehicle is the 1st year following previous recalls. I have been told by the service professionals that they are at a loss whey a recall has not been issued on this issue again. That it is not only an environmental concern, but a huge safety concern. I have contacted Audi America twice now regarding this and ZERO has happened.

Filed Aug 29, 2026 · Engine · PA

The 2017 Audi Q7 Prestige was purchased on November 7,2016. Since the purchase, all service was provided by one or the other of two Audi dealerships. During this period, the Audi recommended 10K, 20K,30K, 40K, 50K, 60K, 70K, and 80K mile services had all been performed. In the almost ten years that I owned the car, the oil and oil filter were changed 11 times at one or the other of the two dealerships. The mileage interval between oil changes was 6,383 miles on average with a maximum interval on 8,177 miles; the time interval between oil changes was 320 days on average with a maximum of 399 days. The engine oil cooler valve had shorted out internally and was replaced in April 2025 at 58,225 miles. By the end of August 2026, the car had travelled 71,375 miles. From 60,000 miles on, oil consumption has gradually increased to alarming levels:1-quart every 700 miles. On August 22, while driving at highway speed on the Pennsylvania turnpike near Pittsburgh, I experienced a sudden loss of power, rapid deceleration, rough running of the engine, and a “Drive System Malfunction “indicator. Fortunately, I was able to slow the vehicle and safely move off the highway. The car was towed ($396) to an Audi dealership. The technician reported that the diagnostic scan showed a misfire code for cylinder #2; and, upon inspection, the #2 spark plug was found to be excessively oil-fouled. When the technician swapped the coils and spark plugs from cylinders #2 and #3, the misfire remained on cylinder #2. A compression test on cylinder #2 showed 120 psi – below normal, but not low enough by itself to definitively condemn the engine. The cost for this analysis was $500. I declined to invest in further teardown of the engine. Audi purchased the vehicle for $4,000. My experience appears similar to others with the 2017 Audi Q7 with the 3.0 engine. Exceptionally poor engineering and total lack of customer care!

Filed Jul 31, 2026 · Engine, Steering · CA

On XXX, I was driving northbound on US-101 from [XXX] to [XXX] to pick up a family member for an appointment. The vehicle had been operating normally at freeway speed. As traffic slowed for a construction zone near Summerland, I intentionally reduced speed to approximately 20 mph. At that point, I heard a sudden abnormal rotational mechanical noise from the engine compartment, best described as a flapping or rubbing sound. The noise had not been present earlier during the drive. Within moments, the engine lost power and shut down. The vehicle lost propulsion while in traffic, and power steering assist was lost after the engine stopped. I was able to safely maneuver the vehicle off the roadway. The engine would not restart. Before this incident, I did not observe any meaningful warning of an impending catastrophic engine failure. I did not observe an engine overheating warning, an oil-pressure warning, or any other dashboard warning indicating an imminent engine seizure. Before purchasing the vehicle, and during my ownership, I used Ross-Tech VCDS (Audi/VW-specific diagnostic software) as part of proactive maintenance and monitoring. Nothing identified an impending catastrophic engine failure. The vehicle was transported to an independent European repair facility for inspection. The shop determined that the engine is mechanically seized and advised that the precise initiating cause cannot be determined without engine disassembly. An Audi dealership likewise indicated that additional manufacturer-level diagnostic procedures would be required. A case was created, and Audi declined assistance. I am submitting this complaint because the engine failed suddenly during normal operation without a meaningful advance warning, resulting in an immediate loss of propulsion in traffic. I believe this type of unexpected catastrophic engine failure presents a potential safety concern if it occurs while the vehicle is being operated on a public roadway. INFORMATION REDACTED PURSUANT TO THE FREEDOM OF INFORMATION ACT (FOIA), 5

Filed Jul 31, 2026 · Electrical, Engine · CA

My 2017 Audi Q7 with the 3.0T engine has experienced repeated engine/ignition system failures. The vehicle displays a "System Malfunction" warning light accompanied by shaking and stalling. This same malfunction has occurred at least 3 separate times over the past few years. Each time, a repair shop diagnosed and replaced faulty ignition coils, and the vehicle ran normally for a period of time before the identical malfunction returned. The vehicle is currently inoperable due to the most recent occurrence. This creates a safety risk because the stalling and shaking can occur while driving, with no clear warning beyond the malfunction light appearing at the same time as the symptoms begin. A stall or loss of power while in motion, especially in traffic or on a highway, could lead to a collision. The problem has been confirmed and repaired multiple times by an independent European auto repair specialist, who stated this is a known, recurring issue with this engine/model. The vehicle has not yet been inspected by the manufacturer directly. Separately, the vehicle has also developed excessive oil consumption, requiring approximately 2 gallons of oil added roughly every 6 weeks, with the frequency increasing over the last 2 months. I am uncertain whether the oil consumption and the recurring coil/ignition failures share a common root cause, but both issues are ongoing and unresolved. The vehicle and its components are available for inspection upon request.

Filed Jun 8, 2026 · Engine, Transmission · VA

I was traveling at highway speeds in active, high-velocity traffic when my vehicle suffered a sudden, catastrophic mechanical failure that nearly resulted in a severe multi-car accident. Without any warning, the vehicle completely lost its ability to accelerate, flatly refusing to pick up speed or maintain momentum despite pressing the gas pedal. ​This unexpected, immediate drop in propulsion marooned me in high-speed lanes, leaving the vehicle dangerously vulnerable as oncoming traffic rapidly closed the distance behind me. Drivers behind me were forced to aggressively swerve and brake to avoid a high-speed rear-end collision. Moments after this life-threatening loss of power occurred, the Check Engine Light illuminated on the dashboard. ​Subsequent technical inspection revealed a severe engineering defect: the internal seals of the factory coolant control components failed, forcing pressurized engine coolant backward into the engine’s primary vacuum system. This pressurized fluid completely contaminated the vacuum lines, the vacuum reservoir tank, and the electronic solenoids—including the N75 boost control solenoid. By filling the vacuum infrastructure with liquid coolant, the engine was instantly starved of its ability to regulate turbocharger boost, triggering a critical "limp mode" and a P0299 underboost fault. ​The catastrophic failure of an internal cooling seal directly compromising an active drivability safety system represents an unreasonable and severe defect. It transforms a routine drive into an immediate, uncontrollable highway hazard. I am filing this report because this known coolant migration pattern presents a clear, present, and life-threatening danger to owners operating this engine platform.

Filed Mar 10, 2026 · Electrical · MA

I am submitting this complaint regarding a safety-related recall on my Audi Q7 involving the alternator. The wording of the recall is significantly underplayed, written off as an emissions issues. When in reality this is a life threatening flaw in the alternator. It is highly concerning that Audi isn’t being transparent with people who are driving these cars and risking their lives while doing so. This is not simply emissions, in reality, the car can totally malfunction while in operation. The entire electrical system fails and the car completely stops responding to the driver, fully stops and dies no matter where you are driving or at what speed. While driving on the highway, my vehicle experienced a catastrophic electrical failure caused by the recalled alternator, which caused the car to completely stop and it would not restart in any way. This created a life-threatening situation for my family and me. As a result of this electrical failure, the vehicle’s battery was damaged, and Audi has acknowledged coverage of 90% for the battery repair. However, the voltage converter, which is part of the same charging system, was also damaged during the same event. Audi is refusing coverage for the $1,600 repair of the voltage converter, despite the damage being caused directly by the alternator failure. I believe this represents a significant safety risk, as the vehicle’s sudden loss of power could lead to serious injury or death. Additionally, the recall itself caused secondary damage that is being denied coverage, which is unfair and unsafe. I am requesting that the federal safety agency review this matter as a safety defect/recall-related failure, and ensure the manufacturer addresses all consequences of this recall-related defect, including coverage of secondary damage like the voltage converter.

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 18, 2025 · Engine · PA

I am reporting a progressive oil consumption defect that led to a catastrophic engine failure in my 2018 Audi Q7. The vehicle was purchased Certified Pre-Owned (CPO). I reported the excessive oil use to an Audi dealer. The dealer attempted to address the issue by performing an engine cleaning/flush, but the engine failed shortly afterwards. Over time, the vehicle required frequent top-offs between service intervals. Eventually, the engine suffered a mechanical failure, resulting in a broken exhaust valve and internal engine damage while driving on the highway. The Audi dealer provided a repair estimate of approximately $12,000. Audi of America offered 40% assistance to make the repair, but does not recognize the underlying excessive oil consumption issue. Furthermore, the proposed repair only replaces the damaged valve and related components, but does not address the underlying excessive oil consumption that caused the failure. This means the vehicle may still: •unexpectedly run low on oil, •lose power while driving, •suffer additional internal damage, or •again experience sudden engine failure while driving. These conditions can cause dangerous drivability issues, including loss of acceleration and potential stalling at highway speeds. This appears to be a serious safety-related defect involving lubrication failure, component breakage, and potential loss of power. I am requesting that the federal safety agency review this issue to determine whether similar failures are occurring in other Audi Q7 vehicles with the 3.0T engine.