IsItAGoodCar
Reliability Guide

Common Problems with the
1997 Audi A6 Mk2 (C5)

The launch year brought a spacious, comfortable cruiser with sophisticated multi-link suspension. Now over 25 years old, every C5 needs careful checks for water ingress through blocked plenum drains and age-related suspension wear.

What changed for 1997

  • •Launch with 1.8T, 2.4 V6, 2.5 TDI, and 2.8 V6 engines
  • •Multi-link aluminium front suspension
  • •Adaptive air suspension option
  • •Sophisticated interior for its era

Common MOT watch-outs

  • !Blocked plenum drains causing water ingress
  • !Front suspension bush and ball-joint wear
  • !ABS module internal solder faults
  • !Instrument cluster pixel failure
5
Known Issues
2
Serious
3
Moderate
0
Minor

All Known Issues

Blocked Plenum Drains

SeriousBodywork & Rust

Leaves and debris block the drains, leading to water entering the cabin and damaging the CCM.

Est. Repair Cost: £100–£800
Warning Signs:

Wet front carpets, Electrical behaving strangely

What to Inspect:
  • Feel the carpet in the front footwells
  • Check under the battery and plenum chamber for standing water or debris
Verified by IsItAGoodCar Research TeamUpdated

2.5 V6 TDI Camshaft and Rocker Wear

SeriousEngine

Early sliding-rocker versions can suffer cam and rocker wear. Later roller-rocker engines differ, so identify the engine code and valve gear before judging the risk.

Warning Signs:

Uneven running, Progressive loss of power or top-end noise

What to Inspect:
  • Request specialist valve-gear inspection if symptoms are present
  • Check correct oil specification and documented timing-belt work
Verified by IsItAGoodCar Research TeamUpdated
Official Recalls & Reference Documents:

Front Multi-Link Suspension Wear

ModerateSuspension & Chassis

The C5 uses a sophisticated aluminium multi-link front suspension with eight control arms per side. Bushings harden and ball joints develop play, causing clunks and vague steering.

Est. Repair Cost: £350–£900
Warning Signs:

Clunking over bumps, Imprecise steering, Uneven tyre wear

What to Inspect:
  • Listen for clunks over potholes
  • Inspect bushes and ball joints visually
  • Check for multiple suspension advisories on MOT
Verified by IsItAGoodCar Research TeamUpdated

ABS Module Failure

ModerateElectrics & Electronics

The Bosch 5.3/5.7 ABS control unit develops internal solder faults, triggering ABS and brake warning lights and sometimes causing speedometer dropouts.

Est. Repair Cost: £200–£500
Warning Signs:

ABS and brake warning lights, Speedometer dropping to zero, Three beeps on startup

What to Inspect:
  • Check dashboard warning lights
  • Scan for ABS fault codes
  • Ask if module has been rebuilt or replaced
Verified by IsItAGoodCar Research TeamUpdated

Driver Door Wiring Loom Breakage

ModerateElectrics & Electronics

Wires in the rubber boot between the body and driver door fatigue and snap over time, causing central locking, window and mirror failures.

Est. Repair Cost: £100–£300
Warning Signs:

Door window stops working, Central locking intermittent, Mirror adjustment fails

What to Inspect:
  • Inspect wiring in the door boot for broken strands
  • Test all door electronics
  • Check for previous repair work on loom
Verified by IsItAGoodCar Research TeamUpdated

Buying Tips for 1997 Audi A6 Mk2 (C5)

  • Feel the front footwell carpets for dampness before anything else
  • Clear plenum drains under the battery and brake servo regularly
  • Check all instrument displays for pixel loss
1998
Check a 1997 Audi A6 Mk2 (C5) by Registration