In this regular column, Autodata’s Technical Team share their fixes to common problems raised through Autodata’s technical helpline, available to all UK customers.
Audi A3 engine cranks but fails to start after parking overnight
Fault:
We have a 2020 Audi A3 in the workshop that fails to start after parking overnight. This is especially noticeable after cold nights; the engine cranks but fails to start. The customer has provided a smartphone video of the issue, but we’ve been unable to replicate it in the workshop. We have however noticed the rear exhaust silencer is split. Have you seen this issue before, and can you give us any pointers on where to start to fix it?
Fix:
Yes, this is a known issue for A3s with the DADA engine code and is specifically a problem when the ambient air temperature drops below 0°C. The cause is condensation build-up in the rear exhaust silencer that freezes and prevents exhaust gas flow. To resolve the issue, inspect the rear exhaust silencer for damage and replace if necessary. To prevent water build-up in the rear exhaust silencer, drill a water drain hole in the rear exhaust silencer with a 3mm drill (Fig 1.3) using the following measurements: Fig 1.1 = 260mm, Fig 1.2 = 235mm.
