Audi A4
Distributor-pump TDI with 81 kW. Robust engine, but injection pump and solenoid can cause issues from 200,000 km. Timing belt every 90,000 km is mandatory.
Solid everyday engine — gets the job done
110 hp 1.9L for daily use. Watch the known weak points. Manual gearbox is pleasantly light.
Engine Weaknesses 5
On the 1.9 TDI AFN, premature timing belt failures from seized idler pulleys have been documented. Service interval was shortened to 90,000 km. Always replace all pulleys and tensioners when changing the belt.
Symptoms: Squealing noises, sudden engine stall, engine damage from valve contact
The distributor injection pump on the 1.9 TDI AFN tends to develop shaft seal leaks. The upper seal is inexpensive (around €20); the lower seal requires reconditioning at a Bosch workshop (around €500).
Symptoms: Diesel smell, visible oil/diesel leak under the injection pump, fuel stains
Mechanical injectors on the AFN wear over time and produce an uneven spray pattern. Difficult starting, black smoke and power loss are typical consequences. Injector testing and reconditioning recommended.
Symptoms: Black smoke, starting difficulties, knock from individual cylinders, power loss
At higher mileages the turbocharger bearings on the AFN can wear. Usually caused by extended oil change intervals or incorrect oil specification. Fixed-geometry turbo is cheaper to replace than VTG variants.
Symptoms: Whining noise, oil consumption, power loss, blue smoke especially after idle
The EGR valve on the 1.9 TDI AFN carbons up from soot deposits and sticks. The typical symptom is a significant power loss. Cleaning is possible but risky — replacement is usually safer.
Symptoms: Power loss, black smoke, rough engine running, increased consumption
Vehicle Weaknesses 5
Despite a fully galvanised body, the A4 B5 rusts at typical spots: door lower edges (behind door strips), bonnet fold at the sides, boot lid, lock panel and roof folds. Rust in roof rails is a well-known long-term issue on many A4 B5s.
The lower straight control arms and their rubber bushings are worn out on almost all older A4 B5s. Characteristic squeaking and knocking noises over bumps. Replacement parts are available cheaply (Lemförder ~€35 each).
Rust-like particles in the A4 B5 coolant reservoir indicate a clogging heater core. The symptom is poor heating performance. At higher mileages, old coolant hoses and the heater core itself must be inspected.
The A4 B5 AC compressor shows first signs of weakness from as little as 60,000 km. Common symptoms are loud noises when the AC is switched on or complete cooling failure. Quality replacement compressors are available.
With increasing age the A4 B5 frequently experiences window regulator motor failure, door lock motor failure, mirror adjustment motor failure and immobiliser transponder failure. These wear issues are typical for a 25+ year old vehicle.