Which parts fail
Components named in complaints (fuel pump, injectors, fuel tank, hybrid and EV propulsion).
Mileage when the problem started
Owner reports
Selected complaints filed with NHTSA by 1998 Audi A6 owners, lightly cleaned up (personal details are redacted by NHTSA).
Fuel was found leaking from the rollover valve nipple on the fuel tank. This nipple has been known to crack when the metal ventilation line line adds stress to the plastic nipple. Gasoline was found in a puddle on the floor at the left/ rear of the car. Audi has recalled and repaired this defect on later year a6s but Audi of America, inc. Refused to repair the 1998 A6. The gas tank on the 98 A6 is identical to the gas tank on the recalled vehicles. The national highway safety administration has already determined that these fuel tanks present a serious fire hazard and participated in a recall. This recall needs to be expanded to include all A6 vehicles with the defective plastic nipple including the 1998 Audi A6 in question.
I own a 1998 Audi A6 quattro (2.8 liter engine). Last winter during a cold spell some part in the pcv valve froze suddenly while driving. This caused the throttle to be stuck at about 4,000 RPM and the car turned into a rocket. Fortunately, I could bring the car to a stop and nobody was hurt. It was quite an experience though, especially since the roads were snowy and icy that day. When I brought the car to the Audi dealer I was told that "it May take a week because we are swamped with many other Audi A6, all with the same problem. I was told that this is some sort of design flaw with this particular model/engine, and that this will happen again in very cold weather. In April I found a short article in "der spiegel" (the german equivalent to newsweek or time magazines), reporting that NHTSA took 16 Audi A6 in to test for exactly this problem. What is your advice to customers? …
(1) purchased auto 10/7/05. Pick-up in miami. Auto has always been operated in florida climate. Drove car to pennsylvania arriving on 10/9/05. On 10/13/05 detected a strong smell of gasoline immediately after refueling and parking in garage. (this was first time car was refueled in pennsylvania and parked in garage). (2) problem diagnosed as a leak in a seam of the plastic gas tank of the Audi A6. Has caused no injuries as yet. Obvious consequence is foul odor and , more importantly, a hazard to the environment and a potential fire hazard. Carfax vehicle history shows no record of the car being involved in an accident, not have I experienced one since purchasing. (3) licensed repair shop is currently searching for replacement gas tank and determining the approximate labor cost to replace.
Consumer contacted dealer regarding recall number 00V137000. Dealer has indicated that parts were not available to take care of the faulty gas gauge which indicated inaccurate fuel reading. This caused vehicle to run out of fuel without warning. Problem has occurred prior to receiving the recall notice. Please provide any further details.
I am experiencing an issue with my vehicle that was recalled by the factory Audi ag but my vehicle was not listed as one of the recalled vehicle. I am afraid of getting stranded due to an improper fuel reading. Please address this accordingly, thank you.
Back pressure develops while refueling, with the engine and ignition off, resulting in fuel being ejected from filler neck. This can and does result in significant fuel spillage with significant risk of injury or death from fire or explosion. This occurs erratically at pumps with a vapor recovery system. Audi has already had a recall for this problem (campaign number: 99V058000, date: 3/22/99) which instructs owners to refuel with the engine off and has added an updated label on the fuel filler door and new instructions in the owner's manual. This is inadequate as this back pressure develops when the engine and ignition are off. I have never refueled with the engine on. This has happened to me multiple times and to date Audi has no solution. My current vehicle is in fact a replacement for a similar vehicle (VIN : [redacted]) with the same problem that I purchased in January 1998. …
I purchased a used 98 Audi A6 pn 4/28/07. When I purchased the car, the only issues with the car were this gassy smell inside the car when you turn on the heat, and a smoke coming from the some pipe. My mechanic told me that the breather was cut, and it had to be replaced . After fixing the problem which I had to pay for. The check engine light went on. Could not do the inspection because of that problem. A few days later I started while driving I hear this beeping sound. The fuel needle immediately went down to empty, and back up again showing that I had half a tank of gas. I went to check it again. The mechanic could not see anything. So I decided to make an appointment with the dealer. In the mean time, I decided to fill up my gas tank. That's when I realized a gas smell coming from outside the car. …
Automobile has run out of gas on 3 separate occasions with fuel gauge displaying anywhere from 1/4 to 3/4 level. Additionally, computer shows anywhere from 70 to 280 miles left until empty. I have been left stranded on the highway on these occasions - twice having to walk to the nearest gas station in terrible weather, once a tow service halped me on the taconic state parkway. Audi replaced all 3 "sending units" on jan 26, 1999 and October 15, 1999. Fuel gauge/sending units have again malfunctioned- I.e. After driving 300 miles on 1 tank of gas, gauge at the 3/4 full level, computer shows 375 miles to empty- an even greater number than previously shown. Contacted both dealership(new country Audi) and Audi of America inc. …
Back pressure develops when refueling with the engine and ignition off. Gasoline gushes out onto attendant, car and ground. Obviously, there is a risk of injury or death from fire or explosion. This has happened many times , so that we no longer fill our tank, as its not nearly as bad if we fill it only 3/4 full. It will still spray out, but not gush out. This is a serious problem which Audi refuses to acknowledge as a defect, even though lives could be at risk.
Fuel gauge does not register the correct amount of fuel, causing the driver to think that there is fuel in the gas tank when, in reality, the tank is empty. This problem could cause a crash because the vehicle just bucks and dies without warning. Vehicle was towed to a Audi dealer for repairs. A fuel sending unit has been ordered. Audi is aware of the problem.repair has been made.
Related recalls
Fuel system, gasoline › Storage › Tank assembly
Vehicle description: passenger vehicles. Sulfur in fuel interacts with certain additives found in widely available gasoline causing sulfur to become deposited on the contact points of three fuel sending units mounted inside the fuel tank.
Remedy: Dealers will remove the existing fuel level sending units and replace them with fuel level sending units using a new alloy composed of gold, silver, and a small amount of nickel, which will not chemically react with…
Fuel system, gasoline › Storage › Tank assembly › Filler pipe and cap
Vehicle description: passenger vehicles equipped with quattro drive system which employs a fuel and fuel vapor leak detection system. If the vehicle is refueled shortly after the engine is started, and is kept running while being refueled, the fuel vapor recovery system could produce sufficient back pressure to cause fuel to be…
Remedy: Vw is providing a new page for the owner's manual and also requesting owners to make an appointment with their dealers to have a label containing important refueling instructions installed inside of the fuel filler…
Fuel system, gasoline › Storage › Tank assembly › Filler pipe and cap
Vehicle description: passenger vehicles. During pre-assembly of the fuel tanks, an incorrect filler neck was installed causing the filler neck to not "match" the fuel cap.
Remedy: Dealers will replace these filler necks.
NHTSA investigations
Stuck-open throttle
Complaints received by odi and Audi allege that, in extreme cold weather, the throttle May unexpectedly fail to return to idle when the accelerator pedal is released, making it difficult to stop the vehicle.in March of 2004, Audi performed a series of tests to investigate the possible causes of throttle icing.Audi concluded that under certain driving conditions - only short distance trips over several weeks where…
Stuck-open throttle
Vwoa has recalled approximately 28,300 my 1998-99 a6 vehicles in cold weather states that experienced the highest rate of throttle icing incidents in the subject vehicles (04v-495).the failure rate in the a4 and passat vehicles is much lower than in the recalled vehicles.odi will continue to monitor the experience in the a4 and passat vehicles.the closing of this investigation does not constitute a finding by NHTSA…
Fuel System complaints in other A6 years
Frequently asked questions
How common are fuel system problems on the 1998 Audi A6?
NHTSA has 35 complaints about the fuel & propulsion system of the 1998 Audi A6, 27% of the model year's 130 complaints. The component named most often is storage › tank assembly (18 mentions).
Is there a recall for 1998 Audi A6 fuel system problems?
Yes — NHTSA recall 01V-157 (tank assembly, May 3, 2001); NHTSA recall 99V-058 (filler pipe and cap, Mar 22, 1999); NHTSA recall 97V-160 (filler pipe and cap, Sep 19, 1997). Recall repairs are free at authorized dealers.
At what mileage do 1998 Audi A6 fuel system problems start?
Half of the complaints with a recorded mileage happened before about 75,000 miles, and 14% before 25,000 miles.
Is it dangerous?
Owners linked 1 crash, 0 fires and 0 injuries to fuel & propulsion system problems on this model year. If you notice symptoms, have the car checked before driving further.
Source: U.S. National Highway Traffic Safety Administration (NHTSA) — owner complaints through October 20, 2026, recalls and defect investigations; fuel economy from the EPA. Complaints are unverified reports and are not proof of a defect. How we rate model years.