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

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
2.5 TDI, 180 PS, 5-speed automatic Research	€536	€3,000	56	Diesel		Automatic (5)	2001–2004
2.5 TDI, 180 PS, 5-speed automatic, all-wheel drive Research	€534	€3,000	56	Diesel		Automatic (5)	2001–2004

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.

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.

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

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.

Operational	€286
Workshop	€137
Fixed costs (tax, insurance)	€127
Total per month	€550
New-car depreciation (not included)	€34

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

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

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