1998 Audi A4 problems

• 1.9 TDI rotary pump (VP37, 1996-2003)

  90–110 hp · 1Z, AHU, AGR, AHH, ALE, ALH, AFN, AVG

  Fiches-auto rates the 90-100 hp 1.9 TDI as the most reliable of the whole family, to the point of recommending buying it "with your eyes closed", with watching the EGR valve in very urban use as the only relevant warning.^[2]

  Buy

Faults that affect 1998 cars

• High severityFrequency: CommonTurboSeized or broken variable-geometry turboThe 1.9 TDI's variable-geometry turbo seizes through carbon build-up or ends up breaking after many kilometres; it appears repeatedly in all the models and outputs consulted, with cases from as early as 22,000 km.Repair (garage): €360–€900Appears at around 22,000 km
• Medium severityFrequency: Very frequentEmissions controlEGR valve clogged with carbonThe 1.9 TDI's EGR valve fills with carbon deposits, especially on short, urban journeys, and it is the fault that appears in the statistics for every model and output consulted, from the rotary pump to the unit injector.Repair (garage): €350–€450Appears at around 50,000 km
• Low severityFrequency: CommonIntakeDirty or faulty air flow meter on the 1.9 TDI (loss of power)The air flow meter is a known weak point of the 1.9 TDI: it gets dirty or gives wrong readings, and the control unit limits the engine, causing a sudden loss of power. It is cheap to fix and does not damage the engine.Repair (garage): €100–€300

• 1.6 8v 100-101 hp (AEK, AFT, ADP, AEH, AKL, APF, BAH; 1994-2008)

  100–101 hp · AEK, AFT, AKS, ADP, AHL, ANA, ARM, AEH, AKL, APF, AUR, AWH, BAH

  Gebrauchtwagenberater describes the 8-valve 1.6 of the Golf IV as an old-fashioned but reliable engine that copes well with regular maintenance, with no known problems in models after 2001. On fiches-auto.fr, no engine fault appears in more than one of the 20 owner accounts for the Audi A3 with this 100 hp 1.6.^[5][6]

  Buy

Faults that affect 1998 cars

• High severityFrequency: OccasionalTimingTiming belt and water pumpThese engines drive the camshaft with a toothed belt and, on the EA113 evolution, that same belt also drives the water pump. A seized pump or an overdue belt can leave you stranded and, if the belt snaps, can damage the engine.Repair (garage): €400–€700
• Medium severityFrequency: OccasionalCoolingCoolant leaks: flange and water pumpCoolant leaks from the cylinder head flange and the water pump are reported on the 8-valve 1.6 and 2.0. It is not a widespread fault, but Motor16 warns that a faulty pump makes the engine overheat without warning: check the level and look for traces of fluid.
• Medium severityFrequency: OccasionalLubricationHigh oil consumptionGebrauchtwagenberater reports high oil consumption on the 2.0 of the Golf IV and relatively high consumption on the petrol León I, without specifying the engine. Fiches-auto.fr adds a case on the 102 hp 1.6. The sources do not identify the responsible part.
• Low severityFrequency: OccasionalElectronicsRough idle, mass airflow meter and lambda sensorsOn the 8-valve 1.6 and 2.0, fiches-auto.fr cites rough idle caused by a dirty throttle or sensor, and mass airflow meter and lambda sensor faults. These are sensor parts, and one owner says they failed the ITV because of emissions.
• Low severityFrequency: RareIgnitionIgnition faults: coils and spark plugsFiches-auto.fr warns of ignition problems on the 1.6s of the Octavia I, and the ADAC, according to Gebrauchtwagenberater, concentrates Golf IV faults on the distributor and coil. There are few documented cases specific to these engines.

• 1.8 T 20v 150 hp (AEB/AGU/ARZ/AUM, 1996-2005)

  150 hp · AEB, AGU, ARZ, AUM

  A German used-car specialist notes that the ignition coils often give trouble on 2001 to 2003 units, and there is a documented case of an unreplaced timing chain tensioner on a 150 hp Passat with 184,000 km.^[9][10]

  With caution

Faults that affect 1998 cars

• High severityFrequency: OccasionalTurboTurbo wear and oil consumptionThe 1.8T turbo can fail over time -cases documented on an Audi TT at 60,000 and 155,000 km- and several sources link it to growing oil consumption in the engine itself. It is not the most cited fault, but it is one of the most expensive when it appears.
• Medium severityFrequency: OccasionalCoolingWater pump failureThe water pump is another documented weak point of the 1.8T: a 180 hp Audi TT had to have it replaced twice, at 110,000 and again at 130,000 km. Coolant leaks "in several places" are also described on a Passat with this engine.Appears at around 110,000 km
• Medium severityFrequency: OccasionalTimingTiming chain tensioner noise and wearAt least one owner documents the timing chain tensioner of this engine left unreplaced, with the resulting chain noise, on a Passat with 184,000 km; another report from a 180 hp Audi TT points to a timing problem at 90,000 km.
• Low severityFrequency: CommonIgnitionIgnition coil failureYes: the ignition coils (one per cylinder) are among the most cited faults of the 1.8T, especially on engines built between 2001 and 2003. They cause hesitation, a rough idle and the engine warning light coming on; usually it is enough to replace the coil of the affected cylinder.
• Low severityFrequency: CommonIntakeAir mass meter (MAF sensor) failureThe air mass meter (MAF sensor) fails fairly often on the 1.8T: on the 150 hp Audi A3 it appears in 3 of the 11 reports collected, and it is also documented on the 180 and 225 hp Audi TT. It causes hesitation and loss of power; it is fixed by replacing the sensor.

• 2.4 V6 30v 136-170 hp (ALW, ARN, ASM, APZ, AMM, AJG, AGA, AML, ALF, APS, ARJ, BDV; 1997-2005)

  136–170 hp · ALW, ARN, ASM, APZ, AMM, AJG, AGA, AML, ALF, APS, ARJ, BDV

  Fiches-auto records 14 reviews of the 170 hp 2.4 V6 A6, with one coil, oil leaks and two catalytic converters replaced at around 190,000 km, and no serious engine faults. These cars are over 20 years old: ask for the invoice for the last belt change (FairGarage gives 120,000 km for the A6 up to 2005).^[14][15]

  With caution

• 2.8 V6 30v 190-193 hp (ACK, APR, AMX, AQD, ALG, ATQ, BBG; 1996-2006)

  190–193 hp · ACK, APR, AMX, AQD, ALG, ATQ, BBG

  There are few reviews (4 of the A6 2.8 V6, 5 of the Passat 2.8 V6 and 1 of the Superb on fiches-auto), and a 2006 forum sees it as durable if maintained, with oil leaks as the main complaint. The belt with water pump and thermostat requires a recent invoice: Audi and VW recommend it every 120,000 km.^{[10][14][16][17][18]}

  With caution

Faults that affect 1998 cars

• Medium severityFrequency: OccasionalTimingTiming belt, tensioner and water pump on the 30v V6On the 2.8 V6 30v the water pump is driven by the timing belt. Audi and VW ask for it to be changed every 120,000 km along with the tensioner, rollers, pump and thermostat, and ContiTech warns that critical errors are often made in this job, especially with the tensioner roller.
• Medium severityFrequency: OccasionalIgnitionFaulty ignition coilsFiches-auto records failed coils on the A6 2.4 V6 and 3.0 V6 (in one case all six at about 85,000 km) and on the A4 3.0 V6; CarWiki lists the coils among the common faults of petrol A6s. Few cases, with no frequency figures.
• Medium severityFrequency: OccasionalCoolingThermostat and water pump leaking or seizedCarWiki lists leaking coolant pumps and seized thermostats among the causes of faults on A6s, and an owner on fiches-auto changed the thermostat after overheating their 2.8 V6 A6. On the 2.8 the pump is driven by the belt, so it is best changed along with it.
• Low severityFrequency: OccasionalLubricationOil leaks and oil consumptionFiches-auto records oil loss on the A6 2.4 V6 (at around 260,000 km) and high consumption on a 2.8 V6 4Motion Passat at 250,000 km, and a 2006 forum calls oil leaks the biggest problem of the 30v 2.8 V6.

• Critical severityFrequency: OccasionalAirbags and safetyDriver's airbag recall over Takata NADI inflator (1997-1999 and 2000-2001 campaigns)Yes: Audi and the EU authorities have included the A4 built between 1997 and 2001 in campaigns over the Takata NADI driver's airbag inflator, which with age may not protect as it should in a crash. The remedy is to inspect the airbag and replace the gas generator at an official service centre; the German press speaks of about an hour's work.
• High severityFrequency: OccasionalSteeringPremature wear of the track rod end ball joints (1999 campaign)In 1999, 38,307 Audi A4s built between March and August 1998 were recalled in the United Kingdom: faulty seals could wear the track rod end ball joints prematurely and, if the warning noises were ignored, the pivot could come loose and affect steering control.