Yet another problem

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mcgregor
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Post by mcgregor »

I hear what you are saying and appreciate your answer but it also makes the noise without the engine going sometimes which, logic tells me rules out both hydraulic pump and flywheel. If the b****r would just do it when I want it to ie outside home in the driveway, it might be easier to diagnose or at least pinpoint a bit better.
Thanks for the thoughts though.
Cheers
Dave
mcgregor
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Post by mcgregor »

OK the b****r is still doing it but it doesn't seem to be effecting the car in any way at the moment so I guess I will be able to have a real good look at the weekend and hopefully pinpoint the source. My current favourite is the diesel fuel filter as that seems to be the only thing that would still be possible without the engine actually going. I tried it again last night at home and of course it would not do it at all! However I did notice that the diesel filter/pipes did actually move slightly when you turned the ignition on meaning to me that there is an instant pressurisation of it. As an aside, surely the filter doesn't take full HDi rail pressure does it. Surely there is a mechanical fuel pump as well to take the common rail up to full pressure. Also is the fuel filter also a pressure regulator? I'm determined to crack this myself and any pointers on how the HDi 110 fuel system works would help me greatly.
Cheers
Dave
pete_wood_uk
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Post by pete_wood_uk »

Are you sure that the original source of the noise is under the bonnet? There's a pump in the top of the tank, under the back seat, and I'm not sure that it goes through any other lift pump from there, I thought it went through the filter and then into the high-pressure pump. Are you getting some sort of transferred noise, caused by vibration or air bubbles or...?

Sorry, this is just BS, all I realy wanted to say was that the pump's in the tank. Well, mine is, anyway.

Pete
Xantia HDi 110 Excl Estate 140k
C5 HDi 138 Estate
mcgregor
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Post by mcgregor »

Thanks Pete. Yup thats how I see it too electric lift pump and then it looks like a mechanical high pressure pump driven off the cambelt by the look of it. No I'm frankly not sure about its source but it definately sounds like under the bonnet as opposed to under the back seat. Can the pump be accessed from below the back seat? My biggest difficulty is that it flatly refuses to do it when I want it to. It usually happens or more likely is hearable at traffic lights when its impossible to check it out. So far it has steadfastly refused to do it outside the house. Sods law I guess.
Dave
Ciaran
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Post by Ciaran »

mcgregor wrote:Thanks Pete. Yup thats how I see it too electric lift pump and then it looks like a mechanical high pressure pump driven off the cambelt by the look of it. No I'm frankly not sure about its source but it definately sounds like under the bonnet as opposed to under the back seat. Can the pump be accessed from below the back seat? My biggest difficulty is that it flatly refuses to do it when I want it to. It usually happens or more likely is hearable at traffic lights when its impossible to check it out. So far it has steadfastly refused to do it outside the house. Sods law I guess.
Dave
I spose all you can do there is go for a long test drive, maybe round the block near your home, until it starts to do it, then stop / return home ASAP and hopefully it'll persist long enough for you to investigate.
mcgregor
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Post by mcgregor »

After ages of faffing about finally got the bugger to make the noise while I was looking at it. Took ages to track down though and it does appear to be coming from the lift pump located under the rear drivers side passenger seat. Funny thing is when I switch off the ignition and then on again it has dissapeared. My problem now is do I do anything about it. Anyone know how easy it is to change out this pump. I looks like it might have a level indicator built into it as well which doesn't exactly fill me with confidence that its a DIY job.
Cheers
Dave
mcgregor
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Post by mcgregor »

Hi Guys
Can anyone at all tell me if the Hdi lift pump is a DIY proposition at all. As far as I can see its also a level indicator. Does it have to be changed in a one or can the pump part be changed on its own. Also can anyone tell me about the fuel line connectors to the pump and the filter how are they removed. Do they just pull off?
Cheers
Dave
Nutcase
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Post by Nutcase »

Hi,
I've got a xsara HDI and although no problem with it as you describe, I can hear the lift pump buzzing each time I turn the ignition switch on (before activating the starter motor). Never hear anything with the engine actually running, probably drowned out by the engine noise!

Is the noise you are describing the same as that initial startup noise as the pump pressurises the fuel line to the engine, or is it a more distinctive tick?

I have seen posts elsewhere on the subject of HDI lift pump failures and several suggesting that wiring faults may be the culprit in some cases rather than the pump itself. I'm wondering if the intermittent noise you are hearing may be due to a poor connection or break in the electrical feed to the pump (ie causing a sort of arcing effect where the pump is in effect switching on and off rapidly, giving a ticking sound. Also whether there is a dodgy relay which is giving the same symptom (I don't if there is a relay or where it might be, so that's just a shot in the dark!)

If you do decide to replace the pump, I did see a pic of a 2ndhand lift pump with attached float on ebay recently, and it looked to me as if it should be straigtforward to remove from the tank, just a case of tilting the pump body as it is lifted up to allow the float and its short arm to manouevre out of the tank opening.

Good luck!
neil123
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1984 2cv Special
Various modern crap!

Buzz?

Post by neil123 »

If this noise is less of a ticking and more of a buzz, or 'brrr' sound... mine was like this for a while and the problem came and went, usually after driving a few miles it would start, could sometimes cure briefly by stopping and restarting motor but would then begin again... if its like that, its the in-tank lift pump (low pressure pump) getting noisy and the fuel pipes above it resonating - try below the OSR seat, see if you can feel the pipes buzzing when its doing it - below the carpet under the seat. I could have SWORN the noise was under the bonnet - it wasn't! Hope that helps.

Neil
neil123
Posts: 102
Joined: 17 Oct 2005, 01:09
Location: Northumberland
My Cars: 2001 Xantia 110 Hdi Forte estate - owned from new.
1984 2cv Special
Various modern crap!

Re: Buzz?

Post by neil123 »

neil123 wrote:If this noise is less of a ticking and more of a buzz, or 'brrr' sound... mine was like this for a while and the problem came and went, usually after driving a few miles it would start, could sometimes cure briefly by stopping and restarting motor but would then begin again... if its like that, its the in-tank lift pump (low pressure pump) getting noisy and the fuel pipes above it resonating - try below the OSR seat, see if you can feel the pipes buzzing when its doing it - below the carpet under the seat. I could have SWORN the noise was under the bonnet - it wasn't! Hope that helps.

Neil
Sorry - I'd only read page 1 before I posted this... you're obviously ahead of me, but at least I can confirm you're right! If the pump is like that on Saxos, its combined with the sender unit and is replaced as one - about £130 IIRC. Neil
mcgregor
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Post by mcgregor »

Thanks Neil. I'm fairly certain that you are right as the symtoms you describe are exactly what I'm getting. As you say it sounds like under the bonnet but I have lifted the rear seat etc when it has done it and the pump sounds like its buzzing. My next question is how long dare I ignore it as it currently does not seem to be causing problems and cashflow is currently a problem, in other words I could well do with putting it off for a while if I can!!
Dave
neil123
Posts: 102
Joined: 17 Oct 2005, 01:09
Location: Northumberland
My Cars: 2001 Xantia 110 Hdi Forte estate - owned from new.
1984 2cv Special
Various modern crap!

Post by neil123 »

mcgregor wrote:Thanks Neil. I'm fairly certain that you are right as the symtoms you describe are exactly what I'm getting. As you say it sounds like under the bonnet but I have lifted the rear seat etc when it has done it and the pump sounds like its buzzing. My next question is how long dare I ignore it as it currently does not seem to be causing problems and cashflow is currently a problem, in other words I could well do with putting it off for a while if I can!!
Dave
Ah, yes, that! Well, mine was done under warranty, but I'm led to believe its one of the HDi's achilles' heels and if it stops, so does yer motor... the job was a quick one, even at the dealership... so I'd guess labour isn't an issue, but the pump's not exactly cheap IIRC - unless you can source one away from Citroen?

Neil
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