P3037high severityPowertrain
Turbo Oil Supply Line Restricted
on 2004-2006 Audi A8 4.2L V8 · AWD
What this code means
The oil supply line to the turbocharger is restricted, reducing oil flow for bearing lubrication and cooling. This will cause premature turbo failure.
Symptoms
- Turbo whine or whistling changing pitch
- Smoke from turbo area
- Reduced turbo performance
- Elevated turbo bearing temperature
- Oil smell from engine bay
- Turbo shaft play increasing
Common causes
- Oil supply line carbon buildup
- Oil supply banjo bolt screen clogged
- Kinked or collapsed oil supply line
- Incorrect oil supply gasket blocking hole
- Sludge in oil feed gallery
Diagnostic steps
- Check oil flow at turbo feed line
- Inspect oil supply banjo bolt and screen
- Check oil return line for restriction
- Monitor turbo bearing temperature if possible
- Inspect turbo shaft for play
Repair notes
Clean or replace turbo oil supply line. Replace banjo bolt screen if clogged. Inspect turbo bearings for damage. Address oil sludge cause.
🔌 Don't have a code reader?
Any of these will read and clear this code — pick by how deep you want to go.
Budget handheld~$40
ANCEL AD410 →
No-phone-needed handheld — reads, clears, live data, freeze frame.
✓ ANCEL official store
Serious DIY~$100
BlueDriver Pro →
Enhanced codes (ABS, airbag, TPMS) plus repair reports.
SHOP FAVORITEShop-grade tablet~$300
Autel MaxiCOM MK808S →
Bidirectional tests, service resets, all systems.
✓ Autel official store
Pro diagnostics$1,500+
Autel MaxiSys MS906 Pro →
Full-system pro platform — topology mapping, ECU coding, the works.
✓ Autel official store
As an Amazon Associate and Autel/ANCEL partner, OLP earns from qualifying purchases — how we link. This never changes the specs we publish.
Other Powertrain codes on this vehicle
00532
Supply Voltage B+ Signal too Low
16394
Camshaft/Crankshaft Position Correlation Bank 1
16395
Camshaft Position Actuator Circuit/Open Bank 1
16486
Mass or Volume Air Flow Circuit Low Input
16487
Mass or Volume Air Flow Circuit High Input
16500
Engine Coolant Temperature Circuit Malfunction
16501
Engine Coolant Temperature Circuit Low Input
16502
Engine Coolant Temperature Circuit High Input
16514
O2 Sensor Circuit Bank 1 Sensor 1
16515
O2 Sensor Circuit Low Voltage Bank 1 Sensor 1