Safety Warning
DIY auto repair can cause serious injury, fire, or vehicle damage. These guides are for informational purposes only. Always follow OEM torque specs, wear PPE, and consult a certified mechanic if you are unsure. You are solely responsible for your safety.
Pump valve unit operation, checking: Notes
2007 Audi S8SECTION Notes
In this test, function of pump valve unit (Left Heat Regulating Valve N175 , Right Heat Regulating Valve N176 and Coolant Pump V50) is checked.
- If the determined temperatures lie below the specification (heating performance too low):
- Check operation of Left Heat Regulating Valve N175 , Right Heat Regulating Valve N176 and Coolant Pump V50 OK? Vehicle Diagnosis, Testing and Information System VAS 5051 in "Guided Fault Finding" function.
If no malfunctions are detected:
- Check for interchanged coolant hoses (from engine to pump valve unit or from pump valve unit to heater cores of air conditioner) →
Pump/valve unit, removing and installing and →
- 19 - ENGINE - COOLING SYSTEM for 4.2 LITER V8 4V ENGINE MECHANICAL, ENGINE CODE(S): BVJ
- 19 - ENGINE - COOLING SYSTEM for 4.2 LITER V8 5V ENGINE MECHANICAL, ENGINE CODE(S): BFM
- 19 - ENGINE - COOLING SYSTEM for 5.2 LITER 10-CYL. 4V ENGINE MECHANICAL, ENGINE CODE(S): BSM
- 19 - COOLING SYSTEM for 6.0 LITER 12-CYL. 4V ENGINE MECHANICAL, ENGINE CODE(S): BSB
- Check for interchanged electrical terminals of Coolant Pump V50 of pump valve unit (direction of pump operation). → Electrical Wiring Diagrams, Troubleshooting and Component Locations
RENDER: 1.0x
NO RELATED
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When to See a Mechanic
Stop DIY work and contact a certified mechanic immediately if any of the following apply:
- • You smell fuel, burning insulation, or see smoke.
- • Brakes feel soft, pull hard to one side, or make grinding noises.
- • The engine overheats, stalls repeatedly, or misfires under load.
- • You are missing required tools, torque specs, or safe lifting equipment.
- • You are not confident in the next step or safety outcome.