Noisy fuel pump, a real puzzler...

[Crazylachesus]

Hi,

Car is 2004 V50 2.4 (140 bhp) 180k km. I had a noisy fuel pump which was making a weird sound after the car has warmed up fully. The sound was a combination of a whirling noise as well as a high pitched squealing noise. After replacing the pump (same Bosch part as before, perfect fit) the squealing noise is gone, but when the car is driven for a while everything gets hot, it starts to make the whirling sound again. It's like the pump is having a hard time pumping the gasoline up, I'm worried it will fry it again... I recorded the sound:

https://youtu.be/qzbYzFBaUag

Anybody has any idea what to look for? Should i change the carbon canister? Or the evap valve? Could something cause a restriction on the return of the outgoing fuel line when the engine gets hot? Any help is greatly appreciated, i'm getting very frustrated about this.

Cheers

[Crazylachesus]

SOLVED!!!

Hi All,

I just wanted to give an update on this, should anybody experience the same problem.

Quick summary

Symptom:
When the car got warm after about ~30 minutes, there was a harsh sound coming from the fuel pump (high pitched noise and also a swirling sound). Also I got P0172 CEL code: system too rich bank 1. It was intermittent, sometimes the CEL went off, sometimes came back.

Resolution:

First try: Changed the fuel pump to the OE BOSCH unit. Did not solve the problem, the high pitched noise went away but the swirling sound stayed. Probably the old fuel pump's motor was already damaged/burnt a bit, that's why it also had a high pithced noise.

Second try: (thanks to a youtube comment) Changed the Fuel Pressure Sensor (https://www.ebay.com/p/VOLVO-Sensor-...sch/1947041485)
It took around 10 minutes (https://www.youtube.com/watch?v=zZkBeSE9kwE) and the problem was solved.

Root cause: The fuel pressure sensor was malfunctioning after warm-up, when the pressure was also rising due to the elevated temperature. It sent a pressure reading too low to the ECU, which didn't let enough pressure back to the return line, so the fuel pressure was actually higher than the factory value. This caused the injectors to let more fuel in the cylinders, that has triggered a "system too rich" CEL code. Also, because of the increased pressure, the fule pump had to work very hard because it was pumping the fuel against a much higher pressure than it should.

I hope this write-off is helpful, and will help to anybody that is experiencing similar problems. It was a real puzzler for me, I'm happy that it's solved now.

Br,
Balint

[GuyM76]

I've just registered on the forum to find out about this issue with my 2007 2.4i. Glad you got your sorted and thanks for posting.

I have replaced my OE fuel pump with a genuine Bosch replacement. Quite expensive as it involved dropping the tank. So disappointed when the noise returned, usually after 20-30 mins gentle driving.

I'll try the pressure sensor and report back. Fingers crossed it works for me as I like the car and have already sunk too much money into it!

[GuyM76]

To confirm - replacing the fuel pressure sensor worked! No complaining or buzzing from the fuel pump anymore.

I didn't read any codes but I am assuming it was the same issue at the OP.

Relieved.

[Clan]

Originally Posted by GuyM76

To confirm - replacing the fuel pressure sensor worked! No complaining or buzzing from the fuel pump anymore.

I didn't read any codes but I am assuming it was the same issue at the OP.

Relieved.

these sensors have been a problem since they came out on the R models .

[MDS40]

Bringing this thread back to life as i have the same symptoms but no fault code .

I get the noise after about 20-30 mins driving so have ordered a new Bosch sensor which should arrive this week.

Anybody else had this problem or can shed more light on it.

[MDS40]

Just to confirm that a new fuel rail pressure sensor cured the noise coming from the in tank pump when warm.

Bosch sensor £50 from genuine supplier against £250 required by Volvo.

[andy_d]

Originally Posted by MDS40

Just to confirm that a new fuel rail pressure sensor cured the noise coming from the in tank pump when warm.

Bosch sensor £50 from genuine supplier against £250 required by Volvo.

oddly, when i asked at the main dealer for a £ on that sensor "oh they dont often go, we never sell many of those" was the reply, and at £50<>£250 i can see why
i did the same, Bosch unit but for a different fault, so far so good

[MDS40]

I had no fault codes ( i have Vida ) just the noise from the pump after 20 mins of driving which at first i thought was the pas pump.

Just for any interested people, i got mine from Opie Oil in Cornwall.
They now seem to sell a lot more than just oil.
I even spotted drive shafts on their site.

Glad you sorted your fault.

[andy_d]

Originally Posted by MDS40

I had no fault codes ( i have Vida ) just the noise from the pump after 20 mins of driving which at first i thought was the pas pump.

Just for any interested people, i got mine from Opie Oil in Cornwall.
They now seem to sell a lot more than just oil.
I even spotted drive shafts on their site.

Glad you sorted your fault.

yes too use Opie in cornwall
i was getting a DIM message about the fuel pressure and vida codes for that sensor,
10 min? job ,even including the pull fuse etc steps
best bit, i Didnt drop the end cap for the pressure relief valve