Audi Q5: Panoramic Sunroof Drain Blockage and A-Pillar Water Ingress

The Q5 panoramic sunroof uses four rubber drain tubes routed through the A and C pillars to channel rainwater away from the cabin. These tubes are known to become blocked with debris or to disconnect from their fittings over time. Water that cannot drain overflows into the headliner, runs down the A-pillar trim, and pools in the footwell — frequently reaching the ECU and Body Control Module (BCM) housed behind the dashboard or under the front seats, causing electrical failures.

• Damp or wet carpet in the front footwells, particularly the driver's side
• Musty or mouldy smell inside the cabin
• Unexplained electrical faults such as random warning lights, window module errors, or audio issues
• Water staining or marks on the A-pillar trim or headliner
• Fogging of interior windows due to elevated cabin humidity

1. 1

   Lift the rubber floor mats and check both front footwells for any signs of moisture, dampness, or staining.

2. 2

   Feel behind the A-pillar trim near the base for moisture.

3. 3

   Inspect the headliner edge at the sunroof seal for water marks or mould.

4. 4

   If access allows, pour a small amount of water into the sunroof drain channels (corners of the glass) and watch for it exiting correctly at the bottom of the A-pillar near the sill — blockage means water will pool inside.

$400 to $3,500 at New Zealand independent workshop rates. That is for this job on its own, not for the car.

An estimate, in NZD, for the repair as normally carried out. What a specific car costs depends on which part has failed and what it damaged on the way — treat this as the floor for a negotiation, not a quote.

• “Has the car ever had water in the footwells or a musty smell in the cabin?”
• “Have the sunroof drain tubes been cleared or replaced?”
• “Have any electrical modules been replaced due to water damage?”

The failure described above is documented in published sources — owner forums, technical service bulletins, recall notices and workshop write-ups — held in our fault database. The inspection instructions and the cost estimate are KickTyres’ own interpretation of them, and it is a starting point for an inspection rather than a manufacturer statement.