AUDI S5 Reliability by YearBest & worst years, problems & recalls — NHTSA data

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.

System malfunctions for new all new 2025 Audi S5 including drive system malfunction, loose wheel, brakes limited functionality, parking break malfunction, stabilization control malfunction, driving dynamics system malfunction, hold assist malfunction.

I began my lease for a brand-new 2025 Audi S5 on July 14, 2025. The vehicle was delivered with a dent in the door, which the dealer repaired before I could take possession. The dent repair was completed on July 22, 2025, at which time I took delivery. On July 23, I informed my sales representative that the SOS/eCall emergency communications system was not functioning. This safety feature, designed to automatically contact emergency services after a crash, has never worked since delivery. I returned the vehicle to the selling dealer on July 28, 2025. As of August 7, 2025, the vehicle remains in the dealer’s service department awaiting repair of the SOS module. No firm completion date has been provided. This defect means the vehicle cannot automatically summon emergency assistance in the event of an accident, creating a significant safety risk to occupants.

Odometer Fraud. The contact purchased a 2019 Audi S5. It was discovered that there was a mileage discrepancy. The vehicle was a private sale. At the time of purchase, the vehicle mileage was 47,796 at the time of registration. The Carfax report, bill of sale and title showed the mileage as 47, 796. it was discovered that the mileage was 75,600 after changing the battery. The BBB and Consumer Protection Agency were contacted.

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.

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.

Water pump failure due to coolant migration.

Our gas tank fuel level sensor is faulty so we can no longer tell how much gas is in our car. The check engine and fuel light are permanently on. This fuel sensor malfunction caused me to run out of gas in the middle of the road. The only way to fix it is to replace the entire gas tank at great expense. We were quoted $3500-$4000. We only have 44K miles on the vehicle.

THE TIRE PRESSURE MONITORING SYSTEM (TPMS) DID NOT FUNCTION AS REQUIRED, AND PRESSURE WAS DANGEROUSLY LOW WHICH SIGNIFICANTLY DAMAGED THE TIRES OVER A VERY SHORT PERIOD OF TIME (2-6 WEEKS). I AM CONCERNED GOING FORWARD IF THE TPMS UTILIZED ON THE S5 DOES NOT FUNCTION AS SHOULD BE EXPECTED PER FEDERAL REGULATIONS. PER 49 CFR 571.138 WHEN PRESSURE OF 1 TIRE UP TO 4 TIRES IS < 25% BELOW COLD INFLATION PRESSURE, A LOW PRESSURE WARNING SHOULD ILLUMINATE AND REMAIN ILLUMINATED. THE TPMS SHOULD HAVE PROVIDED AN ALERT WHEN ONE OR MORE OF MY TIRES WAS AROUND 30 PSI, YET ALL GOT TO UNDER 24 PSI WITH NO WARNING. THE AUDI SERVICE ADVISOR EXPLAINED THAT THE TPMS UTILIZED ON THE S5 IS AN INDIRECT SYSTEM THAT DETECTS CHANGE IN SPEED/CIRCUMFERENCE FOR AN INDIVIDUAL TIRE THAT WOULD INDICATE LOWER PRESSURE, AND IT WILL NOT ALERT IF PRESSURE IN ALL 4 TIRES DECREASES SIMULTANEOUSLY. THIS IS A KNOWN ISSUE, YET AUDI INSISTS THERE IS NO PROBLEM WITH THE SYSTEM FUNCTIONING LIKE THIS. THE OEM TIRES ON THIS VEHICLE ARE VERY LOW PROFILE AND LARGE DECREASE IN PRESSURE IS NOT OBVIOUS FROM VISUAL INSPECTION. SIGNIFICANT PRESSURE REDUCTION OCCURRED MORE RAPIDLY WITH THIS VEHICLE THAN ANY SIMILAR VEHICLES I HAVE OWNED, SO A TPMS THAT CANNOT BE RELIED UPON IS A MAJOR SAFETY CONCERN.

The front driver-side tire experienced a full tire tread separation at highway speeds. It caused minimal damage to the vehicle's rim. No crash, other damage, or injuries occurred. Tire size 255/35R19 96H XL

Fuel gauge does not move at all and showed tank was 5/8 full. However, when I was on the freeway, the vehicle stalled because I was out of gas. Luckily, I was on the right lane and therefore was able to pull over to the side without an incident. This is a new vehicle with faulty fuel sensors. Audi should have QC'd before releasing the vehicle for sale.

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.

Component/System: Passenger Occupant Detection System (PODS) / Airbag system — Recall 74E3 / NHTSA 21V874. What Happened: The passenger airbag may switch off even when the seat is occupied due to a faulty PODS wiring connection. The warning message “Passenger Airbag Off” appears with a chime. This is an active safety recall that was issued before I purchased the vehicle, but the recall was not disclosed at the time of sale. Safety Risk: If the system shuts off the airbag incorrectly, the passenger may have no airbag protection in a crash, creating a serious risk of injury or death. Inspection Availability: Vehicle is available for inspection. I live on the Big Island of Hawaii, where there is no Audi-authorized repair facility. Reproduction/Confirmation: Symptoms match the known recall defect. Audi has confirmed the recall applies to my VIN, but no local dealer exists to inspect or repair it. Manufacturer/Dealer Inspection: Audi has refused to cover shipping to the nearest authorized dealership on Oahu, which is the only location where the recall can be performed. Therefore, the defect has not been inspected due to lack of accessible remedy. Warnings/Symptoms: Airbag warning light illuminates and a message appears indicating the passenger airbag is off, along with a chime. Additional Notes: I cannot safely use or sell the car because the required safety repair is inaccessible. Audi’s refusal to provide transportation makes it impossible to complete the mandated recall.