1998 Audi A4 Quattro Service and Repair Manual

This manual for the 1998 Audi A4 Quattro is built around this exact year, engine and trim, so the torque values, wiring paths, and diagnostic steps you follow are the ones Audi published for the 2.8L V6 (AHA) or 1.8L turbo (AEB) in your car, not a generic A4-era approximation.

Engines covered

• 2.8L V6 — DOHC, naturally aspirated, gasoline
• 1.8L inline-four — DOHC, turbocharged, gasoline

Body styles covered

• 4-door sedan
• 4-door wagon

Trims covered

• Base
• Avant

Known issues on the 1998 A4 Quattro. Six recalls are on federal record for this model year. Two cover aftermarket replacement combination lamps lacking amber side reflectors, which can leave the vehicle poorly illuminated to other drivers. A third covers the steering tie rod seals, where moisture and dust intrusion into the swivel bearing can wear it over time and diminish steering control. A fourth, on automatic-transmission cars, covers a vacuum hose control valve to the brake booster that may not open or close fully in cold temperatures, reducing brake assist. A fifth covers a loosely seated air screen in the air flow meter that can dislodge after a cold-start backfire and prevent the throttle plate from returning to idle. The sixth, and most serious, covers the driver's frontal air bag inflator: without phase-stabilized ammonium nitrate propellant, the inflator can absorb moisture and explode during deployment, or underinflate the air bag, risking serious injury. Owners have filed 262 complaints for the year. The factory diagnostic and repair procedures behind each of those systems are here.

From a driver air bag inflator inspection to a cold-weather brake booster check or a steering tie rod seal replacement, it keeps you on the OEM procedure and the correct specification for your specific 1998 A4 Quattro.