The contact owns a 2014 Audi S5. The contact stated that after starting the vehicle, there was a Control Area Network (CAN) bus system unit TCM error, power brake, and engine failure. The TPMS warning light was illuminated. The dealer was contacted and was unable to determine the cause of the failure. However, the dealer wanted to replace the CAN bus unit. The vehicle was not repaired. The manufacturer was made aware of the failure. The failure mileage was 70,662.
NHTSA complaint #11756778 — an unverified report by a vehicle owner.
The contact owns a 2025 Audi S5. The contact stated that while driving at an undisclosed speed, the vehicle lost automotive power. There was no warning light illuminated. The vehicle failed to respond while attempting to drive. The vehicle was restarted after the failure. The vehicle was taken to the dealer; however, the vehicle was not diagnosed or repaired. The manufacturer was made aware of the failure and informed the contact that the issue could be related to a lane switch failure. The approximate failure mileage was 8,577.
NHTSA complaint #11733376 — an unverified report by a vehicle owner.
I am writing to file a formal safety defect complaint regarding the EA839 3.0T turbocharged V6 engine installed in various Audi models, including but not limited to the B9/B9.5 S4 and S5, C8 A6 and A7, and 4M/4M.5 Q7 and Q8 (model years approximately 2017 onward). This engine has a well-documented issue with piston skirt wear and failure, which I believe constitutes a significant safety hazard due to the potential for sudden engine failure and loss of vehicle power while driving. As an owner of a 2019 Audi S5, I have experienced symptoms related to this defect, and I urge the NHTSA to investigate this matter to prevent potential accidents, injuries, or fatalities.
NHTSA complaint #11712240 — an unverified report by a vehicle owner.
An Audi dealer has just diagnosed my 2018 S5 Cabriolet Prestige with vacuum system contamination caused by water pump failure. I had requested the diagnostic due to small coolant leaks on the engine and loss of coolant in the expansion tank. No warning lights and no overheating yet. Not yet aware of any loss of performance. I have been advised it is unsafe to continue driving the car. Dealer has quoted me $7800 estimate to repair the car. Purchased the car in 2021 as a Certified Pre Owned vehicle, and it now has about 84K miles on the OD.
NHTSA complaint #11704929 — an unverified report by a vehicle owner.
Upon starting the vehicle while parked on 10/18/2025, dashboard displayed warning: "Turn off engine and check coolant level. See owner's manual." Visual inspection revealed coolant residue on mechanical coolant pump switching valve N649 on cylinder head bank 1, indicating water pump internal seal failure allowing coolant to leak into vacuum control system. Component failed: Water pump (EA839 3.0T engine) - vacuum-actuated design with internal seal failure. Component available for inspection. Safety risk: This documented design defect in EA839 engines can cause sudden drivetrain malfunction and loss of power while driving. While discovered parked in this instance, the same failure mode has caused P0299 codes (turbo under-boost) and "Drivetrain Malfunction" warnings in other vehicles, creating dangerous loss of power situations. Dealer confirmation: Not yet inspected by dealer. Pending diagnostic appointment. Warning symptoms: Dashboard coolant warning message was first indication of problem. No prior symptoms observed. Known defect: This is a widespread issue affecting 2018-2024 Audi models with EA839 2.9T/3.0T engines (S4, S5, RS5, SQ5, A6, A7, S6, S7, A8, Q7, Q8). Audi has issued Technical Service Bulletins MC-10245526-0001 and MC-10172894-0001 acknowledging coolant pump leak issues. No recall has been issued despite documented failures across multiple model years.
NHTSA complaint #11703321 — an unverified report by a vehicle owner.
Known-Best Assesment-Piston Skirt Defect and Non-Disclosure of Prior Issues: Approximately only three months after purchase of a brand new 2025 Audi S5 on 6/11/25 , I received a letter from Audi of America acknowledging a potential piston skirt defect/failure resulting from faulty material and/or workmanship. They extended the part warranty for 8 years or 80,000 miles but this doesn't help me feel safe driving this vehicle. I was informed the defect cannot be proactively repaired and would only be addressed after failure. This instruction is unreasonable, unsafe, and contrary to the purpose of purchasing a new vehicle. Audi has previously settled piston-related class litigation, yet no one at Audi Henderson disclosed any history of piston issues during the sale. Had I been informed of this material risk, I would not have purchased the vehicle. I now feel unable to safely or confidently use this vehicle for long-distance or out-of-state travel. Upon researching it I found this: The mileage at which a piston skirt defect will cause total failure varies widely, potentially from mere miles to tens of thousands of miles, or could last the entire life of the engine if it's a minor defect. It is highly risky to drive with a known defect, as damage accumulates over time and can lead to a complete and sudden engine failure and could lead to catastrophic, potentially deadly consequences. Factors Affecting the Rate of Worsening :The time frame for failure depends almost entirely on the nature and severity of the initial problem, as well as driving habits. * Severity of the Defect: A small scuff might not cause issues for a long time, while a cracked or broken skirt can lead to catastrophic failure very quickly (e.g., within 5 miles or even minutes). * Maintenance: Regular oil checks and changes help manage the symptoms but cannot prevent eventual failure if the defect is significant. * Early reports: Some drivers have reported problems with low-mileage vehicles.
NHTSA complaint #11701588 — an unverified report by a vehicle owner.
VEHICLE Year: 2018 Make: Audi Model: S5 Prestige Trim: 3.0 TFSI (EA839 V6 Turbo) Mileage: 86,000 Engine Code: CWGD COMPLAINT TITLE Latent Engine Failure – EA839 Piston Skirt + Rocker Arm Defects – Dealer Broke Engine Cover, Left Wiring Harness Dangling – Audi Denies Despite Having DIY Receipts For Maintenance DESCRIPTION At 86,000 miles, my 2018 Audi S5 Prestige suffered internal engine failure from metal debris and cylinder wall scoring. Dealer borescope showed: Metal in oil filter (bearing + non-ferrous “other metal”) Deep scoring on multiple cylinders No check engine light. No power loss yet. Still drivable — but seizure is imminent. DEALER NEGLIGENCE AT [Audi Of Chantilly] (Penske Automotive Group): Engine cover broken — not reported Wiring harness retainers/harness clips left undone on both sides after spark plug removal → Improper reassembly risks damage to harness and engine/components — safety hazard. This matches TWO known EA839 defects: Piston Skirt Cracking – Sept 2025 Warranty Extension covers identical symptoms (debris + scoring). Denied only for 6,000 miles over 80k cap. Pre-06/2018 Rocker Arm Needle Bearing Failure – Audi revised mid-2018 (PN 06M109417H → 0P2109417, double bearing size) because originals shed metal. Garage Auto Sports: “Known to fail… Audi fixed it.” Link AudiWorld: 200+ cases Link AoA DENIAL – FALSE “Over mileage” → Rocker defect has no cap “Undocumented maintenance” LIE → All oil changes DIY with Audi 508.00 oil + OEM filters → Amazon invoices attached → Never asked for proof $32,000 quote. 100% denial. SAFETY RISK Sudden seizure at speed No warning Dealer damage worsens risk REQUESTED ACTION Investigate EA839 2017–2018 for piston + rocker failures Recall / extend warranty for pre-06/2018 builds Probe denials without proof request + dealer negligence ATTACHMENTS Denial letter Dealer Diagnostic 32k Quote Borescope report Amazon receipts Broken cover + undone retainers photos Screenshots (links above)
NHTSA complaint #11699716 — an unverified report by a vehicle owner.
To Whom It May Concern, I am submitting this complaint to report a mechanical issue with my 2018 Audi S5 Sportback. Around 57,000 miles, the engine began making a noticeable ticking noise, which I have been advised is due to failing rocker arms. This issue has raised serious concerns, as it can lead to engine misfires, reduced performance, and potentially catastrophic engine damage if left unresolved. The problem appeared without warning, despite regular maintenance and no prior engine alerts. I believe this may be a defect affecting other Audi models with similar engines, and I urge the NHTSA to investigate whether a recall or technical service bulletin should be issued. Vehicle Information: Make: Audi Model: S5 Sportback Year: 2018
NHTSA complaint #11672422 — an unverified report by a vehicle owner.
The car stalled while driving on [XXX] while approaching Express EZpass toll on [XXX]. The car stayed in the middle of the fast lane until the tow truck driver came and started the car. I cannot recall the yellow message on the dashboard that appeared as soon as the engine stopped. A yellow triangle with exclamation point and a car with exclamation point appeared on the dashboard. We called 911 and then AAA. AAA on the phone instructed us to turn on and off the engine several times. The engine did not start until the tow truck driver came, opened the door and replaced me in the driver’s seat. He stepped on the brakes and pushed the start button as I did several times before but this time the car started as if nothing happened. We drove the car home. The Audi service checked the car on their first available appointment date, 4/14/25. Their report stated “scanned vehicle and found faults starter performance performed test plan and starter is working in good condition, inspected battery terminal and found then not tight enough, performed cleaning of both battery terminal and reinstalling them and after service was performed now vehicle is working as it designed to” The car had its 40K maintenance service on 9/4/2024. Mileage then was 32,869. INFORMATION REDACTED PURSUANT TO THE FREEDOM OF INFORMATION ACT (FOIA), 5 U.S.C. 552(B)(6)
NHTSA complaint #11655629 — an unverified report by a vehicle owner.
While driving, my Audi overheated randomly, started smoking, had to be towed. Had 72,800 miles, was serviced by Audi at 70k miles and all prior recommended services. Towed to Audi dealership, quoted 29k in engine repairs, Audi could never tell me why engine overheated. Would not cover any expense because “i didn’t buy it there”. Insurance denied two claims because Audi reported it as engine failure although they couldn’t prove what happened to cause the heating, said it was one of the worst engine overheating they had seen. Prior to overheating, service driver system popped up for the first time. Temperature gauges were normal. Will not start or run since. No accountability taken by Audi at all, even through corporate. I believe my safety was at risk because the engine would have caught on fire had I not of noticed or pulled over. A Good Samaritan even pulled behind me to check on me because they saw it smoking in passing. I have a video of Audi inspection. Date is estimate of event, I would have to research. Vehicle was purchased by prior owner as cpo from Audi at 30k miles and serviced since at same Audi dealer every recommended service and prior if issue arose, I have all service records.
NHTSA complaint #11647150 — an unverified report by a vehicle owner.
After driving for 7 to 8 minutes less that 45 mph, a yellow warning lamp and an audible warning indicating unsafe coolant temperature displayed on the dash. An overheating engine is unsafe for me and drivers near me. I immediately pulled over and turned off the A/C. I then turned on the heater, and after 15 minutes slowly drove 5 minutes to a repair shop (Import Autohaus, Hull Street). The repair shop diagnosed a defective water pump. The pump has not been inspected by anyone other than the mechanics at the repair shop.
NHTSA complaint #11600570 — an unverified report by a vehicle owner.
I received a coolant overheating message, pulled to side of road. Let vehicle cool off although it just showed coolant warning and actual engine temperature showed normal along with oil temperature. Started car back up and it was ok, drove about a mile, engine started steaming, white smoke out of exhaust, system failure had to pull off and be towed. Engine is destroyed at 72,833 miles.
NHTSA complaint #11579095 — an unverified report by a vehicle owner.
I was returning home from visiting family. My drive was approx 140 miles home. The car was running/driving normally when I stopped at a gas station to get a snack. When I came back to my car and attempted to start it, it would not start and had camshaft and crankshaft sensor DTC's. I had to tow the car to my repair shop who determined that the issue was the rocker arms. Despite performing regular maintenance above and beyond what the manufacturer recommends, two rocker arms fell apart inside the engine (needle bearings came out) and sent metal through the engine, causing it to need to be replaced. It was later determined that this was a known issue by Audi, and that they redesigned the rocker arms at a later date. The did not issue a recall or any extended warranty for the effected models. This cost me $16,349 out of pocket to repair. I contacted Audi several times and they refused to rectify the issue. I have came across several others who have experienced the same issue. I have supporting documentation as well as part numbers and dates that I can provide upon request. This type of issue is a saftey concern because this can leave a driver stranded. When this issue happend I was over 75 miles away from home. Luckily I was able to find a tow truck and had the funds to cover the expense of having the car towed back to my home town. However, this issue could leave someone stranded in the middle of nowhere if they werent as lucky as I was.
NHTSA complaint #11558380 — an unverified report by a vehicle owner.
I smelled a super strong gas smell from my car leaking somewhere in the engine hidden by other parts, it smells so bad it’s hard to be in the car it’s a fire hazard. Due to the fuel the car hardly starts due to the fuel not getting to the engine
NHTSA complaint #11516443 — an unverified report by a vehicle owner.
I own an Audi 2015 S5 Cabriolet. I bought this new from Strong Audi in Salt Lake City. On September 2, 2022, I was driving it on I 15 south of Provo UT. I was in the middle of 5 lanes of traffic all driving approximately 80/miles per hour. Suddenly, the engine shut down. Thank God the drivers around me were able to avoid me as I had to coast to the right lane at very slow speed. As explained by the service representative at Strong Audi my vehicle has a tendency to vapor-lock in high temperatures resulting in the engine shutting down! He further explained that parts were available for $ 2,200 to correct the situation, but since my vehicle was out of warranty this would be my responsibility. I am of course having the work done.
NHTSA complaint #11485974 — an unverified report by a vehicle owner.
The 2018 year for the Audi S5 has a notorious rocker arm failure within the engine. Audi is aware of this problem because they have revised the part for later build dates. However, they have failed to remedy the issue for the vehicles that fall within the problematic build dates. Once this failure occurs, it is catastrophic and will require a new engine.
NHTSA complaint #11480742 — an unverified report by a vehicle owner.
MY VEHICLE AS WELL AS MANY AUDIS WITH THE MECHATRONIC SYSTEM ARE HAVING AN ISSUE THAT PRESENT A ERROR, " MECHATRONIC FAILURE TPMS GEARBOX MALFUNCTION). IT OFTEN EITHER NOT DRIVABLE, EVEN WHEN IN TRAFFIC OR DRIVES AT A SNAIL'S PACE WHEN ATTEMPTING TO EXIT TRAFFIC. AUDI CORPORATE SAID A RECALL IS ONLY DONE WHEN THE NHTSA FEEL THAT'S IT A ISSUE THAT CAN CALLS SAFETY &/OR DEATH. THIS SEEM TO EFFECT, FROM MY RESEARCH, 2010 - 2014 AUDI S4, S5 AND A5 MODEL [N THE USA AND THERE ARE SOME EUROPE COMPLAINTS, WHICH I HAVE FOUND AS WELL] MANUFACTORED AT A PARTICULAR PLANT OR PROVIDER. THIS TYPE OF MALFUNCTION CAN CERTAINLY CAUSE 'LOSS OF LIFE' AS IT OCCURS IN TRAFFIC. I HAPPEN TO LIVE IN METRO ATLANTA GA, WITH OUR FAST PACE TRAFFIC, ITS A SERIOUS ISSUE. THERE ABSOLUTELY SHOULD BE A RECALL. THE COST TO REPAIR CAN BE UP TO $15K. THERE IS NO WAY THIS SHOULD HAPPED TO A $60-$75 HIGH-END VEHICLE. HAVE VIDEO'S OF THE DASHBOARD WITH THE ERROR AND CAN UPLOAD TO YOU. I WAS OFFERED 15% ON THE REPAIR, WHICH IS REALLY AN INSULT. PLEASE LOOK INTO THIS ISSUE AND ITS NOT HARD TO FIND OTHERS WITH THIS ISSUE. I PRAY FOR SOME RELIEF IN THE FORM OF A RECALL. IT HAS BEEN HAPPENING SINE 2010, FROM WHAT I HAVE LEARNED.
NHTSA complaint #11235288 — an unverified report by a vehicle owner.
MAXIMUM OIL LIGHT WARNING LIGHT, REDUCE OIL LEVEL, SINCE PURCHASED. GASOLINE GETTING INTO OIL. REMOVED 9 QUARTS OF GASOLINE SATURATED OIL OUT OF CAR. AUDI SAYS I NEED TO DRIVE CAR MORE. AUDI RECENTLY REPLACED OIL & FILTER AND SAID TO MONITOR . DROVE CAR FROM DEALERSHIP SERVICE, WARNING LIGHT CAME BACK ON, CHECKED ENGINE WITH AFTER MARKET OIL DIP STICK, STONE SMELL OF GAS IN OIL. VEHICLE TOWED BACK TO DEALERSHIP
NHTSA complaint #11164757 — an unverified report by a vehicle owner.