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
1998 Audi A6 Mk2 (C5)
We've identified 4 known issues that can affect the 1998 Audi A6 Mk2 (C5). 1 of these are serious faults that could be expensive to repair.
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 1998 Audi A6 Mk2 (C5)
- ✓Check the front carpets for dampness (blocked plenum drains)
- ✓The multi-link front suspension is complex and expensive to refresh
- ✓1.8T models need proof of regular oil changes