1990 Audi 100 Service and Repair Manual

This 1990 Audi 100 factory service and repair manual is built around the 2.3L five-cylinder (engine code NF) as delivered in the Base Sedan, so the specifications, wiring, and torque values inside track this exact car rather than an averaged, multi-year printing.

Engines covered

• 2.3L inline-five — SOHC, naturally aspirated, gasoline

Body styles covered

• 4-door sedan

Trims covered

• Base

Known issues on the 1990 100. Four recalls are on federal record for this model year. The first covers the transaxle: differential oil is lost over time to evaporation, and the resulting low oil level causes premature bearing and gear wear, up to loss of drive-wheel power or the front wheels locking and rapid deceleration. The second covers the gas filler door placard, which omitted the required vehicle capacity weight label under FMVSS 110. The third covers the trunk-mounted jack instruction label, which is incorrect for the jack actually supplied, risking incorrect use and jack collapse. The fourth covers the frontal air bag sensor and control module, which can fail to meet Audi's durability standards over the vehicle's lifetime and inadvertently deploy the air bag without warning. Owners have filed 16 complaints for the year. The factory diagnostic and repair procedures behind each of those systems are here.

From a differential oil check to correcting the jack label or working through the air bag sensor circuit, it keeps you on the OEM procedure and the correct specification for your specific 1990 100.