1998 Audi A6 Service and Repair Manual

This manual for the 1998 Audi A6 is built around the 2.8L V6 (engine code AHA) and Base sedan configuration, so the specifications and procedures inside match the hardware actually under the hood rather than a generic A6-family writeup.

Engines covered

• 2.8L V6 — DOHC, naturally aspirated, gasoline

Body styles covered

• 4-door sedan

Trims covered

• Base

Known issues on the 1998 A6. Ten recalls are on federal record for this model year. The driver's front air bag inflator can absorb moisture and deploy improperly in a crash. The headlight switch connector can short-circuit, which could lead to overheating or fire. Sulfur buildup on the fuel sending units can make the gauge read full when the tank is not, so drivers can run out of fuel without warning. Tie rod seals in the steering linkage may fail to seal, letting moisture and dust wear the swivel bearing and diminish steering control. Contact between the knee bolster and the headlight switch wiring harness can cause an electrical short and a fire originating in the left dashboard area. On automatic-transmission cars, a vacuum hose control valve may not open or close fully below -4°F, reducing vacuum to the brake booster. On automatics with the 2.8L V6 5-valve engine, ice can accumulate in the throttle body in extreme cold and freeze the throttle open, so the vehicle may fail to reduce speed when the driver lifts off the gas, which could result in a crash without warning. An incorrect fuel filler neck was installed on some vehicles and does not match the fuel cap, allowing fuel to escape near an ignition source. On Quattro vehicles, refueling with the engine running can build back pressure in the fuel vapor recovery system and eject fuel spray when the nozzle is removed. If the engine backfires during a cold start, a loosely seated air screen in the air flow meter can become damaged, and screen pieces could enter the intake air flow system and prevent the throttle plate from returning to its full idle position. Owners have filed 134 complaints for the year. The factory diagnostic and repair procedures behind each of those systems are here.

From tracing an intermittent headlight short to a fuel tank sending unit check or a Quattro-specific service interval, it keeps you on the OEM procedure and the correct specification for your specific 1998 A6.