Audi / Vehicle-specific diagnosis
Audi A8 P2279/P0507 and a warm-idle whistle: the two-check breather diagnosis
The useful question is whether both observations were recorded on this vehicle.
Check the vehicle first.
- Vehicle
- 2013–2016 Audi A8, 4.0 TFSI.
- Reviewed bulletin
- 2040644/13; factory displays P227900 and P050700.
Match the complaint before naming the part
Audi describes a metallic whistle or grinding noise, usually at warm idle, sometimes with an intermittent warning lamp. A leaking crankcase-breather pressure regulator can produce that combination. The code descriptions concern an intake leak or unexpectedly high idle.
Both checks are required
The workshop compares the noise with Audi’s reference recording and checks whether opening the filler cap changes it. The documented replacement branch requires both results.
| Observed result | What it supports |
|---|---|
| Reference sound matches; cap opening affects it | The bulletin directs oil-separator/breather replacement. |
| Only one result matches | The stated replacement condition is incomplete. |
| Noise cannot be reproduced | An unobserved result must not be recorded as a passed check. |
Make an intermittent complaint reproducible
For your service booking, describe when you noticed the sound and whether the engine had already warmed up. If you already have a safe recording, bring it. Do not lean into a running engine or open the filler cap to create a demonstration yourself.
Ask the technician to document the two findings separately. “Sounds like a breather” and “both prescribed observations matched” communicate different amounts of evidence.
What this guide does not establish
This article does not establish a cause for every engine noise or every intake-leak fault. A different engine, an absent symptom or an incomplete comparison leaves the proposed repair insufficiently supported by this particular document.
Before collecting the car, ask how the workshop checked your original complaint after the repair. Keep the findings with the invoice so a later recurrence can be compared with what was actually observed. These are editorial documentation suggestions.
Source documents
- 2040644/13 (2022-03-25)
Source reviewed .