Blocked Plenum Drains
SeriousBodywork & RustLeaves and debris block the drains, leading to water entering the cabin and damaging the CCM.
Est. Repair Cost: £100–£800
Reliability GuideCommon Problems with the
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
4
Known Issues
1
Serious
3
Moderate
0
Minor
All Known Issues
Front Multi-Link Suspension Wear
ModerateSuspension & ChassisThe 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
ABS Module Failure
ModerateElectrics & ElectronicsThe 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
Driver Door Wiring Loom Breakage
ModerateElectrics & ElectronicsWires 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
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