Skip the auto shop - Our mechanics make house calls

Q: Please help with my Volvo

asked by on

Hey, 09 Volvo s80 t6 AWD, takes 2-3 tries to start in the mornings, i can shut it right off and then it will start no problem. Also very loud noise when revving (in gear or not, moving or not) for the first 20 or so minutes. CEL P0171 comes up sometimes but most times goes away after a bit of driving. Fuel Pressure at 60psi when running but in the morning turned ignition on psi went from 0 to 30 in 2 seconds and stayed there until I started the car. Any ideas?

My car has 125000 miles.
My car has an automatic transmission.

For your car, the specifications for your fuel pressure is about 30 psi to 60 psi depending on the load. Your fuel pressure should hold the pressure to the injection system overnight and only leak down about 5 psi from what it was when you shut off the car.

If the fuel pressure drops to zero or close to it in less than half an hour then you have a fuel pressure leak down problem. The leak down can be the fuel pump check valve or one of the injectors leaking.

The most common problem is the fuel pump not maintaining the pressure after shutting off the engine but do not rule out a leaking injector.

As for the noise, this may be the fuel pump whining to try and keep the increased fuel pressure up to specifications.

My recommendation is to have the system diagnosed by a mechanic, such as one from YourMechanic. We will have special fuel testing tools that are needed to check your vehicles fuel system along with the loud noise that you are hearing.

Was this answer helpful?

Need advice from certified mechanic? Get help now!

Over 1000 mechanics are ready to answer your question.
The statements expressed above are only for informational purposes and should be independently verified. Please see our terms of service for more details

Ask a Mechanic
(100% Free)

Have a car question? Get free advice from our top-rated mechanics.

Ask A Mechanic
Over 10,000 questions answered!

Get an instant quote for your car

Our certified mechanics come to you ・Backed by 12-month, 12,000-mile guarantee・Fair and transparent pricing

Get a quote

What others are asking

Q: Vibration and noise experienced at the front left wheel.

Hi there. The vibration could be the wheel hub assembly worn or the CV Shaft moving around. The wheel is attached to a wheel hub assembly which is attached to the steering suspension on the car, so the wheel will...

Q: Overheating

Hello, It sounds like you have had nearly most of the cooling system replaced recently. Aside from having cooling system leaks, the only other way for coolant to be escaping would be via evaporation (in some cases this can happen...

Q: Whining noise when the engine is at idle.

Hi there. The whining noise that you are hearing is the gears and timing chain in the engine. This is a normal condition and all of the Porsche engines have the same sound. If your engine has an inner cooler,...

Related articles

How Do Power Car Windows Increase Passenger Safety?
Power windows are responsible for approximately 2,000 emergency room visits every year. When a power window closes, it exerts enough force to bruise or break bones, crush fingers, or restrict an airway. Though...
P0052 OBD-II Trouble Code: HO2S Heater Control Circuit High (Bank 2 Sensor 1)
P0052 code definition HO2S Heater Control Circuit High (Bank 2 Sensor 1) What the...
P0240 OBD-II Trouble Code: Turbocharger Boost Sensor B Circuit Range/Performance
P0240 code definition Turbocharger Boost Sensor B Circuit Range/Performance What the P0240 code means P0240 is an OBD-II generic code triggered when the Engine Control Module (ECM) detects the intake boost...