KNOWN FAULTS · Audi

Audi A4 (B5) common problems.

2000–2001 · Petrol / Diesel

Sources are not verified in real time and no entry confirms that your car is affected.

4 known faults with sources

Engines: 1.6 / 1.8 / 1.8 T (Petrol)

Applies if: Only the 1.8 T.

Ignition coils on the 20-valve 1.8 TEngine

Engine / equipment: 20-valve 1.8 T: Golf IV, Bora, Passat B5, Audi A3 8L and A4 B5, Seat León
Period mentioned: Approx. 2001–2003
Symptoms: Misfires, hesitation and the engine light; the engine runs on one cylinder fewer.
Possible cause described: The individual coils on 1.8 T engines from those years failed frequently. The German guide quotes about €100–200 for coils and leads.
Check for the garage: Read the per-cylinder misfire codes and replace the affected coil (preferably with a revised one).
Cost cited in the source: Approx. €100–200 for coils and leads (German guide).A rough figure from the original database, not an up-to-date quote.

Engines: 1.6 / 1.8 / 1.8 T (Petrol) · 2.4 / 2.8 V6 (Petrol) · S4 (2.7 biturbo) (Petrol) · 1.9 TDI (Diesel) · 2.5 TDI V6 (Diesel)

Applies if: Defects documented by US recalls; European cars may have equivalent campaigns: check by VIN.

Ignition switch, steering joints, air-flow meter and airbag on the Audi A4 B5Known weak points

Engine / equipment: Audi A4 B5 (petrol, S4 and TDI)
Period mentioned: 1995–2001
Symptoms: A plastic ignition-switch housing that breaks (1996–1997); steering tie-rod seals letting in water and dust and wearing the joint (1998–1999); an air-flow-meter screen damaged by backfires on cold starts (1998); a brake-servo vacuum-hose valve on automatics (1997–1999); an intermittent horn from a poor earth; non-azide driver-airbag inflators that can rupture (1997–2002); an airbag that fires from static electricity in low humidity (1996–1997).
Possible cause described: Defects documented by US recalls; European cars may have equivalent campaigns: check by VIN.
Check for the garage: Check airbag campaigns by VIN; check steering play.
Cost cited in the source: No verified estimate; ask the garage for a quote.A rough figure from the original database, not an up-to-date quote.

Engines: 1.9 TDI (Diesel)

PD TDI camshaft, injectors and cylinder headInjection / cylinder head

Engine / equipment: 1.2, 1.4, 1.9 and 2.0 TDI unit-injector (PD) engines, including the VW-sourced 2.0 CRD in Chrysler, Dodge and Jeep
Period mentioned: 2000–2010
Symptoms: Growing noise from the cylinder head, power loss and rough running (cams and lifters); unstable idle, smoke or hesitation (injectors); on the 16-valve 2.0 TDI, coolant loss with no visible leak from a cracked head.
Possible cause described: The camshaft also drives the unit injectors and carries a heavy load: without VW 505.01 oil the lobes and lifters wear. 2.0 TDI PD injectors fail frequently. Some 16-valve 2.0 TDI heads (part number ending in A) crack; VW considered it fixed by the end of 2006.
Check for the garage: Check the oil history (VW 505.01), listen to the head, check injector balance rates with a diagnostic tool and, on the 16-valve 2.0 TDI, read the head part number (03G 103 351) and look for coolant loss.
Cost cited in the source: Camshaft and lifters: approx. €400–800; 2.0 TDI PD injectors: €900–2,000A rough figure from the original database, not an up-to-date quote.

Mileage cited in the database: 120,000–200,000 km. This is not a maintenance interval and does not predict a failure.

Engines: 2.5 TDI V6 (Diesel)

Worn camshafts, air mass meter and injection pump on the 2.5 TDI V6Engine

Engine / equipment: 2.5 TDI V6 with distributor pump: Audi A4 (B5 and B6), A6 (C5) and VW Passat B5
Period mentioned: 1997–2005
Symptoms: An engine that runs rough, loss of power or hesitation; now and then the injection pump fails; oil leaks from the engine or gearbox.
Possible cause described: AUTO BILD (March 2008) reports more and more complaints about the A4's 2.5 V6 because of worn camshafts (Audi did not issue a recall) and adds that the Multitronic gearbox fails mainly with this engine, because of its high torque. On the A6 (1997–2004), AUTO BILD lists faulty air mass meters causing loss of power or hesitation, injection pumps that fail now and then and oil leaks from the engine and gearbox, mainly on the TDI. The Passat B5 has the same engine.
Check for the garage: If the engine gets noisier or runs worse with the miles, have the garage check the camshafts by removing the cam covers. Read the codes and test the air mass meter before touching the pump. With the Multitronic gearbox, ask for its history and check that it does not jerk or slip.
Cost cited in the source: No verified estimate; ask the garage for a quote.A rough figure from the original database, not an up-to-date quote.