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.

A: For your car, the specifications for your f...

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: Wont start after timing belt replacement

If you are getting fuel and compression, then you need to check to see if you have spark. If you do not have spark then test the ignition system or crankshaft sensor using a scan tool. If your engine was...

Q: Check engine flashing and loss of power - 2009 Chevy Equinox

Hello. A flashing Check Engine Light is a warning that an urgent issue has occurred. A flashing Check Engine Light signifies that the computer has detected a failure that may potentially cause damage to the vehicle's emission system. Continuing to...

Q: when placing gear shifter in reverse I hear a pop/knock.

Hello. A popping / clunking noise when moving in reverse can be caused by many things. Two of the most common causes for those symptoms are worn axles or motor mounts. The axles are the joints that transmit power from...

Related articles

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 P0052 code means This code is seen when the Engine Control Module (ECM) tries to control 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...
P2428 OBD-II Trouble Code: Exhaust Gas Temperature Too High Bank 1
P2428 code definition A P2428 trouble code signifies that the PCM has detected a problem in the exhaust gas temperature sensor circuit in bank 1, which subsequently contains the number one...