Audi A4 loss of power problems

Filed Jul 2, 2026 · Electrical, Transmission · CA

A vehicle diagnostic scan dated 04/15/2026 at approximately 88,502 miles showed a stored transmission electronics fault: P084100, described as “Transmission fluid pressure sensor/switch A range/performance,” with status listed as passive/sporadic. This indicates a transmission / powertrain control concern involving the transmission fluid pressure sensor, transmission electronics, wiring, control logic, pressure monitoring, or related powertrain components. The vehicle also has prior transmission/powertrain history, including a March 2023 transmission-pan-gasket concern documented in service records, so this later transmission electronics fault is being reported in that broader powertrain context. This is being reported as a safety concern because a transmission fluid pressure sensor or transmission-control fault can affect shifting, drivability, delayed engagement, slipping, harsh shifting, limp mode, reduced power, drivetrain damage, or loss of propulsion while driving. Even if the fault is intermittent, a transmission-control issue may create an unsafe condition if it occurs in traffic or during acceleration, merging, turning, or normal driving. No crash, fire, injury, or fatality occurred. The vehicle/component is available for inspection, and the diagnostic scan report, transmission-related records, service records, manufacturer communications, and related communications are available if requested.

Filed Nov 19, 2025 · Engine · CA

The timing chain and tensioner in my 2014 Audi A4 Quattro (VIN: [XXX] ) failed without warning, causing the engine to suddenly stall and become inoperable while in motion. This presented a serious safety hazard. Although my vehicle is slightly outside the settlement mileage and time limit, timing chains are considered a lifetime component and are not a maintenance item, meaning they are not expected to fail and are not listed as requiring inspection or replacement under any Audi maintenance schedule. This failure was sudden, catastrophic, and safety-related. Audi and Volkswagen have already acknowledged this timing chain defect in federal class-action litigation (Opheim et al. v. Volkswagen Group of America), and my VIN is included in the affected vehicle list. Audi’s own dealership technician confirmed that the timing chain is stretched, the tensioner is fully extended, and the intake camshaft timing is off by a tooth—clearly matching the known defect. The vehicle stalled suddenly while arriving at a repair facility, and it would not restart. Had this occurred on a highway, a collision could have easily resulted. This is a known safety defect, affecting engine timing, power loss, and stall risk. The manufacturer denies responsibility despite known defects, safety implications, and VIN eligibility. I am requesting the federal safety agency to investigate Audi’s refusal to address a known and documented safety-related defect involving a critical non-maintenance engine component that is expected to last the life of the vehicle. INFORMATION REDACTED PURSUANT TO THE FREEDOM OF INFORMATION ACT (FOIA), 5 U.S.C. 552(B)(6)

Filed Aug 18, 2025 · Engine · VA

The turbocharger wastegate actuator failed suddenly at highway speeds, causing loss of engine power and making it extremely difficult to maintain highway speeds. The warnings that suddenly appeared caused the cruise control to cease working as well. The dealership (Audi Miami South by The Collection) inspected the vehicle and confirmed the wastegate actuator seized, requiring a complete replacement of the turbocharger. The vehicle has 53,000 miles.

Filed Nov 13, 2023 · Engine · FL

Loss of power / Turning onto oncoming traffic there was severe hesitation. Which caused the car to not move onto oncoming traffic quick enough causing both oncoming vehicles to maneuver around. Upon going to the mechanic he states I have oil in the engine from faulty piston rings which he states he has seen multiple times in these models.

Filed Mar 11, 2023 · Engine · NJ

With out warning vehicle engine shut down in the middle of the highway causing loss of power to breaks and steering. Mechanics assessment states engine is mechanically or electrically blocked. Upon investigating issue I found numerous law suits regarding engine piston failure. Please see civil action docket number L-001632-21. Found on class action .org

Filed Oct 15, 2021 · Driver assistance, Engine · OR

2013 Audi A4 with a 2.0 turbo engine approximately 62.5K miles and up to date with all services. I was driving on the highway at highway speeds when the engine suddenly started to misfire with a partial loss of power making the car difficult to steer. At that time the check engine light was not illuminated. I was able to get off the highway and drive home about 2 miles away from when the misfires first occurred. The police did not get involved as I was able to return home. The following week the car was towed to my mechanic where it was diagnosed that cylinder 3 had a problem. At that time the check engine light illuminated. He recommended that I tow my car to the Audi dealership as they have better availability of parts. The dealer took apart the engine and diagnosed a broken piston ring which destroyed many other parts of the engine. The engine had to be replaced with a new one from the factory. Audi should be held accountable for catastrophic engine failures that may result in injury to others due to poor engine design.

Filed Aug 23, 2021 · Electrical, Transmission · MD

PRNDS appeared in red on my dash and then started blinking. Went on line regarding this and read about a TCM switch or a lever switch malfunction.Have an appt with mechanic on 8/26/21. From what I have read we are looking at a cost prohibitive repair of several thousands of dollars. Does Audi have any responsibility? Apparently it is a common complaint with the A4 model. Felt loss of power when decelerating.

Filed Dec 31, 2020 · Brakes, Engine · 138,000 miles · CA

Tl* the contact owns a 2012 audi a4. The contact stated while driving approximately 40 MPH, the check engine and low oil pressure warning lights illuminated. The vehicle was taken to an independent mechanic, where it was diagnosed with needing the engine coils and spark plugs to be replaced. While driving after the vehicle was repaired, the vehicle experienced the same symptoms as before with the addition of loss of power steering and power brakes. The contact stated that the steering wheel was difficult to turn and difficult for the brake pedal to be depressed. The contact was unable to restart vehicle and the vehicle was towed to an independent mechanic to be diagnosed. The contact was informed that the timing chain needed to be replaced. The vehicle was not repaired. The manufacturer was informed of the failure. The failure mileage was approximately 138,000

Filed Sep 15, 2020 · Engine, Fuel system · 110,000 miles · NY

Audi issued a technical service bulletin that I found on your website. This bulletin was regarding the exact parts the dealer (audi) identified as being affected on my car (high pressure fuel pump, cam follower, and corresponding intake camshaft cam lobe). This bulletin (not a recall, but distributed internally to dealerships) clearly states that this is a widespread issue that affected all VIN ranges of specified audi models from 2005-2007 that included mine. Audi extended drivetrain coverage on these vehicles to 10yr/120k mi. This issue causes a worsening loss of power upon accelerating (making driving at all speeds dangerous) and eventual engine failure if left alone. I am the 3rd owner of this car, so I did not receive the intended letter from audi stating the specifics of this coverage extension. My vehicle is currently at ~110k miles at the time of this service (~4-5 days ago). Upon bringing this bulletin to the attention of audi service manager, he did not ask me for the bulletin number or revision, he just denied covering it verbally saying the coverage was "10yr/120k mi, whichever came first" but would not send me a copy of the extension letter proving this. The cost of repairs related to this issue is ~$5,600. I opened a case with audi of america. I provided the requested info, and was still not sent/emailed a copy of this letter, or proof that it was sent to the owner of the vehicle. I was told cases take up to a week to review (they would need me to provide service records for the vehicle, etc). I was called less than 24hrs later that the case was denied, before I provided any info or pled my case that a company with the slogan "truth in engineering" should stand behind an acknowledged engineering flaw. Repairs are ~1.5x the value of the car. I don't have the money to fix this and it creates an unsafe driving condition. Please help.

Filed Jul 27, 2020 · Engine · 87,000 miles · TX

The car started losing power when stepping on the gas to go faster or up a ramp or merging into the freeway. I took my car to the mechanic I trust. He checked my car and stated it is losing power in the fourth cylinder. He did the spark plugs and other tests, I'm not good remembering the names. States he would need to do a rebuild or replacement of the engine. The car has only 87,000 miles. Doent make any sense.