Noise coming from Bosch injector pump, mostly when cold

[Elgaucho]

Hi there,

I hoping some of you pug gurus can help.
I have a year 2000 2L HDI. Recently I been getting a noise , fixed pitch coming out of the diesel injector pump (Bosch). It comes on with the igniton, then knocks off after approx 7 secs. It definitely in the pump, if I remove the diesel hose going into it , noise disappears. Its sounds like a vibrating solenoid or something.
Its not affecting startup or engine running, and noise decreases after it warms up, though it is getting worse. (ie not decreasing as much when warm. )

Anyone know what happens on the ignition sequence, is the pump primed then cuts out at the certain pressure? There 2 electrical connections going into the pump, it this a solenoid and pressures sensor. ?

I'm expecting something to finally give up, just wondering can I get individual electronics for the pump, or will i have to get the whole pump.

Any advice greatly appreciated.

[Doggy]

It is relativley common for the in-tank electic fuel lift pump to become noisy prior to failure - this does indeed run for some seconds when the ignition is turned on, (4 seconds has been mentioned), then turns off. I wonder if the noise from this unit is being conducted through the pipework to the HP pump, making you think that's where the problem lies? (It's interesting that it's quiet with the supply pipe disconnected).

The HP pump is engine driven, via the cambelt and shouldn't make any noise while stationary.

There is a 3rd piston disable solenoid valve on the pump, but it normally changes state at about 3000 RPM, so shouldn't be audible as you describe.

[OdinEidolon]

It is relativley common for the in-tank electic fuel lift pump to become noisy prior to failure - this does indeed run for some seconds when the ignition is turned on, (4 seconds has been mentioned), then turns off. I wonder if the noise from this unit is being conducted through the pipework to the HP pump, making you think that's where the problem lies? (It's interesting that it's quiet with the supply pipe disconnected).

The HP pump is engine driven, via the cambelt and shouldn't make any noise while stationary.

There is a 3rd piston disable solenoid valve on the pump, but it normally changes state at about 3000 RPM, so shouldn't be audible as you describe.

the lift pump is noisy also when new. I fitted a brand new Bosch original one last year and it was noisy from the first day.

[Elgaucho]

It is relativley common for the in-tank electic fuel lift pump to become noisy prior to failure - this does indeed run for some seconds when the ignition is turned on, (4 seconds has been mentioned), then turns off. I wonder if the noise from this unit is being conducted through the pipework to the HP pump, making you think that's where the problem lies? (It's interesting that it's quiet with the supply pipe disconnected).

The HP pump is engine driven, via the cambelt and shouldn't make any noise while stationary.

There is a 3rd piston disable solenoid valve on the pump, but it normally changes state at about 3000 RPM, so shouldn't be audible as you describe.

Just to clarify , if cuts off after 7 secs or so if I don't start the car. If I start the car it stays whining. Do you think the noise would travel all the way from tank at the rear? Whats the function of the piston disable valve? Thanks for the input, by the way.

[Elgaucho]

I just though I write back and let you guys know how I resolved this. I replaced the fuel filter holder.
I initially just went in to reseat the filter, but I snapped off one of the hose ends while tightening it. (it's very tight).
I got a replacement from the wreckers for 30 €. In reality though, the filter just need proper seating, the rest was collateral damage.
Thanks for the help and suggestions, so I took so long to post back, I just got a reminder email to the thread

[steve_earwig]

I didn't know the board did that My inbox should be heaving with reminders (instead of assorted junk )

Thanks for getting back to us with your solution That wasn't a bad price either.