Audi A6 C5 (1997-2004): known problems and buying guide

Built: 1997–2001
Median price: €2,299
Listings: 233
Running cost per month: €532–€565
Power: 165 PS (121 kW)
Reliability: 2/5
DIY: 2/5

Buy only with timing-belt and camshaft records for the 2.5 V6 TDI, and avoid a multitronic with judder or no service history.

Updated 27 October 2026

All versions

Variant	Running cost per month	Median price	Listings	Fuel	Engine codes	Gearbox	Production years
2.4, 165 PS, 5-speed manual	€532	€2,222	51	Petrol		Manual (5)	1997–2001
2.4, 165 PS, 5-speed manual, all-wheel drive	€565	€2,222	51	Petrol		Manual (5)	1997–2001

At a glance

Built 1997 to 2004 as saloon, Avant and allroad, front-drive or quattro. The facelift runs from 2001.
Reliability: 2/5. The 2.5 V6 TDI camshafts and the multitronic judder are the main faults.
DIY: 2/5. Buyer checks need no tools, but the timing belt job needs major disassembly.
Prefer: manual gearboxes, and petrol engines with a dated timing-belt record.
Avoid: 2.5 V6 TDI cars with no camshaft or timing-belt record, and multitronic cars with judder or no oil service record.

Engines and gearboxes

1.8 20V (125 PS): no fault confirmed in the sources read.
1.8 T (150 PS): the fan viscous coupling wears after about 200,000 km, and a failed one can cause overheating (whataboutauto, kolesa.ru).
2.0 (130 PS, facelift only): no fault confirmed in the sources read.
2.4 V6 (165/170 PS): no fault confirmed in the sources read.
2.8 V6 (193 PS): no fault confirmed in the sources read.
2.7 V6 biturbo (230/250 PS): no fault confirmed in the sources read.
3.0 V6 (220 PS, facelift only): no fault confirmed in the sources read.
4.2 V8 (300 PS) and S6 (340 PS): no fault confirmed in the sources read.
RS6 4.2 biturbo (450/480 PS): its five-speed tiptronic has the torque converter issue below. No engine fault confirmed in the sources read.
1.9 TDI (110-130 PS): no fault confirmed in the sources read for the 110 and 116 PS. See the VW pump-injector TDI guide for the 130 PS pump-injector.
2.5 V6 TDI (150-180 PS; codes AFB, AKN, AKE, BAU, BDG, BDH): camshaft and follower wear, injection pump and timing belt faults. Mostly cars built before 2002. See Known issues.

Gearboxes:

Manual (5- and 6-speed): no fault confirmed in the sources read.
Tiptronic (4- and 5-speed): shifting jerks, slipping and a worn torque converter are reported, from about 150,000 km. See Known issues.
Multitronic (front-drive only, from late 1999): judder and control-unit faults. Avoid one without a service record. See Known issues.

Known issues

Issue	Affects	Typical km	Repair cost
2.5 V6 TDI camshaft and follower wear	2.5 V6 TDI, mainly cars built before 2002	Not stated	No confirmed price
Multitronic judder and control unit	Multitronic (front-drive)	About 100,000 km	No confirmed price
2.5 V6 TDI timing belt and water pump	2.5 V6 TDI	60,000-80,000 miles (about 97,000-129,000 km)	About EUR 1,000 (Germany, year not stated, AUTO BILD)
Tiptronic shifting and torque converter	4- and 5-speed tiptronic, including RS6	150,000-200,000 km	GBP 3,500-4,000 for an RS6 torque converter rebuild (UK, year not stated, PistonHeads)
2.5 V6 TDI injection pump	2.5 V6 TDI	Not stated	No confirmed price
Water in the footwell and comfort module	All models	Not stated	No confirmed price
Front suspension wishbones and joints	All models	80,000-100,000 km	No confirmed price
Brittle brake hoses	All models, mainly cars over five years old	Not stated	No confirmed price

Before you buy

Multitronic: test drive from a stop. Jerking on pull-away or speed surges are a bad sign. Ask for oil service records. Needs a scanner: read the control-unit fault memory, where any stored fault is a bad sign.
Tiptronic: on a test drive, revs rising without speed (slipping), late or harsh shifts, or a warning light are bad signs. Needs a scanner: read the gearbox fault memory. Ask for fluid service records.
2.5 V6 TDI camshaft: after a cold start, listen for tapping or knocking from the top of the engine. Rough idle or power loss is a bad sign too. Ask for camshaft and lifter work records.
2.5 V6 TDI timing belt: ask for the record of the timing belt and water pump change. No record, or a change longer ago than 60,000 miles (about 97,000 km), is a bad sign.
2.5 V6 TDI injection pump: do a cold start. Hard starting, stalling, black smoke or a lit check-engine light is a bad sign.
Front suspension: on a bumpy road, listen for clonks from the front. Knocks over bumps or a loose steering feel are a bad sign. No tools needed.
Water in the footwell: lift the carpets under the front seats and check for damp or a musty smell. Check the bulkhead drain holes for blockage. Damp carpets or blocked drains are a bad sign.
Brittle brake hoses: look at the rubber hoses at each wheel for cracks or swelling. Cracked or swollen hoses are a bad sign.

Running costs

Operational	€291
Workshop	€125
Fixed costs (tax, insurance)	€123
Total per month	€539
New-car depreciation (not included)	€36

ADAC figures for 15,000 km a year over 60 months

Market

Listings on mobile.de priced up to 50,000 EUR, 29 October 2026.

Find offers on mobile.de

Listings: 233
25th percentile: €1,400
Median price: €2,299
75th percentile: €3,199
Median mileage: 239,206 km
Median first registration: 1999
Dealer share: 18%
Price at 100,000 km: €3,147

To check a listing's price, open its variant in the table above. Each variant page has a price check.

In detail

2.5 V6 TDI camshaft and follower wear

On the 2.5 V6 TDI, the camshafts, rockers and hydraulic lifters wear. Symptoms are tapping or knocking, power loss, rough idle and higher fuel use. The cause is poor lubrication and weak hydraulic lifters. Most reports are on earlier cars: the garage sources say mainly pre-2002 cars, and kolesa.ru says the wear was fixed in 2003. A drive2 owner logbook names the codes AFB, AKN, AKE, BAU, BDG and BDH. Fix: replace the worn camshafts and the related lifters or rockers. Use synthetic oil and change it on time.

Sources: European Auto Pro, whataboutauto, kolesa.ru, drive2 logbook

Multitronic judder and control unit

The multitronic is a continuously variable gearbox, fitted to front-drive cars only, from late 1999. The A4 uses the same gearbox, and the sources cover it too. Symptoms are jerking or judder when pulling away, speed surges, slipping, flashing PRND lights, no reverse, and in some cases no start. The first-generation control unit (TCU) often fails, typically around 100,000 km. The chain can need replacing after about 100,000 km, and the ECU is a common failure point. Skipped oil changes and oil loss from a hose or the radiator outlet are named causes. Fix: replace the control unit, the chain or the whole gearbox.

Sources: gebrauchtwagenberater.de, AUTO BILD, whataboutauto, Multitronic.ru

2.5 V6 TDI timing belt and water pump

The timing belt and the water pump of the 2.5 V6 TDI wear out. A worn belt or pump causes ticking, coolant leaks, overheating and misfires. A belt failure has high consequences. Change the belt, water pump and tensioner together, every 60,000-80,000 miles (about 97,000-129,000 km), depending on driving. The job needs major disassembly. Cost: about EUR 1,000 for the belt replacement (Germany, AUTO BILD, year not stated).

Sources: European Auto Pro, AUTO BILD, whataboutauto, kolesa.ru

Tiptronic shifting and torque converter

Symptoms are delayed or rough shifts, slipping, vibration and a warning light. On the RS6, the torque converter can cause jarring changes and disconnection under power. Causes are worn internal parts, low or dirty fluid, and a worn oil pump and clutches. Shifting faults start from about 150,000 to 200,000 km. Minor cases are fixed by a fluid flush. Severe cases need internal repair or replacement. On the RS6 a fluid change might help a torque converter fault. A torque converter rebuild costs GBP 3,500-4,000 (UK, PistonHeads, year not stated).

Sources: European Auto Pro, whataboutauto, AUTO BILD, PistonHeads RS6 guide

2.5 V6 TDI injection pump

The injection pump of the 2.5 V6 TDI causes hard cold starts, rough idle or stalling, power loss, black smoke and a check-engine light. Causes are wear, poor fuel and weak lubrication. Fix: rebuild or replace the pump, use clean fuel and change the filters regularly. kolesa.ru calls the pump weak on the 2.5 TDI.

Sources: European Auto Pro, kolesa.ru

Water in the footwell and comfort module

Blocked body drains and plenum drain holes let water into the car. The water soaks the carpets and reaches the electronics. Water in the comfort control module, under a front seat, causes window, central-locking and cabin-light faults. Blocked body drains can also let water reach the vacuum brake booster. Keeping the drains clear prevents it. The sources give no fix or cost for the module.

Sources: whataboutauto, kolesa.ru, PistonHeads RS6 guide

Front suspension wishbones and joints

Front-axle parts wear out. Symptoms are clonks and knocks from the front and a rattling front axle. Causes are brittle rubber bearings, worn wishbones and steering joints, and rough use. Tie-rod ends wear at about 100,000 km. The front suspension lasts about 80,000-100,000 km. The aluminium front parts cost the most, and the lower rear arms wear fastest. A reader survey links worn wishbones and joints to off-road use. No confirmed price.

Sources: AUTO BILD quattro, AUTO BILD, whataboutauto

Brittle brake hoses

Brake hoses become brittle with age. AUTO BILD's inspectors often criticise them from the fifth year on. Pre-2000 cars need brake hose checks. The sources give no price.

Sources: AUTO BILD, whataboutauto

Maintenance

Timing belt and water pump on petrol engines: change about every 60,000 km, with the water pump (kolesa.ru, whataboutauto).
Multitronic oil: change every 30,000 to 60,000 km. The sources differ. Skipped changes are a named cause of failure (Multitronic.ru, gebrauchtwagenberater.de).
Body drains: keep the body drains clear. Blocked drains cause the water faults above (whataboutauto).

Recalls

No recall was found in the sources read; check open campaigns by VIN with an Audi dealer.