V70 new Bosch fuel pump whine, same as old one. Topic is solved

Pppatric · Post by **Pppatric** » 12 May 2021, 19:38

Hello, greetings from Poland.
I have a strange puzzle to solve, in my Volvo V70 2.0t 2006 (595+ Chassis). Last year the original fuel pump started to wine, so I replaced the pump with a new one made by Bosch, same as the original one.
Unfortunately, it did not solve my problem with winning/howling loud under the car.

I found a few cases on forums. It could be a fuel pressure regulator or a fuel pressure sensor, unfortunately I couldn't find any of them in my car.
I ve checked the fuel rail, without cover. No sensors.
The fuel filter is new.

The car runs ok, problem is noise

The howling is continuous from the time I start the car until I turnn off, when the voltage fluctuates, wine changes for a moment.

No matter how much fuel is in the tank, the noise comes from the new pump, 100%.

I have no idea where to look next.

Any advice would be great.

Greetings

Post by **abscate** » 12 May 2021, 19:55

Cseźć !

( I think )

The 2006 uses a pump electric module (PEM) to control the pump and these often get dirty amd fail.

The PEM is either in the trunk area or on top of the fuel tank on the right side.

Post by **oragex** » 13 May 2021, 01:56

Can you read the fuel pressure ? On the plastic tanks, the pump has a hose right underneath it - that goes to the other half of the tank. When the pump is lowered inside the tank, this hose may kink right under the pump and cause a restriction - this is why one person must pull on the hose from the other opening, while a second person is lowering the pump inside the tank.
By the way, I suggest keeping the tank above 50% despite the fuel pump being submerged inside the cooling cup

Post by **jonesg** » 13 May 2021, 02:13

Pppatric wrote: ↑12 May 2021, 19:38 Hello, greetings from Poland.
I have a strange puzzle to solve, in my Volvo V70 2.0t 2006 (595+ Chassis). Last year the original fuel pump started to wine, so I replaced the pump with a new one made by Bosch, same as the original one.
Unfortunately, it did not solve my problem with winning/howling loud under the car.

I found a few cases on forums. It could be a fuel pressure regulator or a fuel pressure sensor, unfortunately I couldn't find any of them in my car.
I ve checked the fuel rail, without cover. No sensors.
The fuel filter is new.

The car runs ok, problem is noise

The howling is continuous from the time I start the car until I turnn off, when the voltage fluctuates, wine changes for a moment.

No matter how much fuel is in the tank, the noise comes from the new pump, 100%.

I have no idea where to look next.

Any advice would be great.

Greetings

I'd say it may not be the fuel pump you're hearing.
You can try pull the haldex fuse, in the rear fuse panel, maybe #17?

Pppatric · Post by **Pppatric** » 13 May 2021, 02:47

Hello.

I was trying to find pem module, as I thought the same, unfortunately no luck.
It is not in the trunk, next to spare wheel and also couldn't see it at top of plastic tank.
But I still think it should have pem module right?

About the fuel line between tank parts.
Do you think it would bend itself somehow?
Whining noise came out with old pump installed, before anything was touched inside the tank.
It was progressing slowly, untill I could hear it from 12 feet, so a bit too loud for fuel pump.

I think I can try to measure pressure.

Thank you for clue about haldex, I have front wheel drive only, so this one for shure not.

Post by **oragex** » 13 May 2021, 06:21

No, the hose between the pump and the second sender bends only when a pump is replaced - and you would have noticed it anyway when removing the old pump. I wrote that more as a caution for future work. I wonder if there is a restriction somewhere , may want to look at the fuel lines under the car (lift securely on jack stands), most lines are secured inside plastic covers so should be fine. Perhaps also look at the line going around the engine, near the crank pulley as well. On the XC90 the PEM is sometimes located in front of one of the rear wheel arches, behind the plastic lines. On other cars it may be located under the rear left seat, under a coin of the carpet, may lift the bottom bench by pulling upwards on one of the sides with force. The plastic tanks do not have the PEM located on top of the tank, only the metal ones

Did you replace the entire pump assembly or only the metal pump cylinder ? The pump plastic cup has some anti return rubber valve at the bottom that may get clogged.

Pppatric · Post by **Pppatric** » 13 May 2021, 17:15

Hey.

Thanks for trying to help, I can see your quesses are very accurate, I already checked fuel lines, nothing is bend or broken.

New pump is whole unit.

About this pem, it is strange, because I couldn't find it under rear left passenger seat.
Did a little research in past about it location, but no luck.

About wheel arch area, I will do some crankshaft seal replacement during the weekend, so I will take a look.
Would be funny, if Volvo hidden it there at V70.

Also I will take a look for fuel lines in engine compartment, checked only under the car.

Thanks for the clues.

jgadbois · Post by **jgadbois** » 18 May 2021, 17:27

I just replaced my fuel pump (again) this past weekend. Prior to removal I printed out the wiring diagram for my 2006 XC70. (This diagram also covers 2006 V70) The PEM is optional for some configurations so you may not have one.

My problem was the fuel line in the tank as oragex suggested. The pump duty cycle started out high at 42% when first installed and climbed to 70% over a couple weeks. The pump noise increased with duty cycle.

Proper routing of the fuel line inside the tank is very critical.

Pppatric · Post by **Pppatric** » 20 May 2021, 08:06

Hello.

Appreciate your suggestion.

Getting a bit desperate, today after driving through a big puddle, after few miles when I get home, and tried to park, car started weaving rpms from 500 up to 1500, and stalled a bit.
After a moment it stopped.

Then I was looking for pem module, in wheel arches, thinking like maybe water flooded it, still no luck.
I start to think there is no pem module in my car.

Only thing about this fuel line that does not click for me is, that old pump before anything was touched, was quiet and started to progressively whine over time.

New one whines from begging, question is could the fuel line bend itself somehow?

Regards

Pppatric · Post by **Pppatric** » 21 May 2021, 02:49

I have a new conclusion about the topic.

1 one is problem with whining started after mechanic did a big job with all engine seals and pcv system.

Maybe fuel line in engine compartment is bend somewhere?

Second one, is that I bought injector rings, and they were also changed during the job mentioned above.

My mechanic changed orings, and after that pump started to progressively whine.

My question is, if this orings 1346393 fit 06 V70 2.0t, and if not as I quess can they leak so bad to make the pump whine?

On fcp it says they are wrong, in Netherlands biggest Volvo supplier, says they are good for all Volvo's from 240 up to V70.
I am sure, the one I have ordered were same size, and in video linked guy says, ttheydifferent in size. Upper one and lower one.

My question is, if this orings 1346393 fit 06 V70 2.0t, and if not as I quess can they leak so bad to make the pump whine?

Regards