Citroen C5 HDi engine dies

Post by **myglaren** » 26 Sep 2009, 11:21

Did you take it right out?
The filter gets clogged and restricts the flow of fuel although the pump will buzz.
You may need to remove the screen filter and clean it.

The pumps do fail too and may be trying to pump and failing. They are known to generate fine metallic swarf when failing that gets into the diesel filter.
If the filter is changed and swarf allowed to enter the filter housing, this goes on to damage the HP pump - very, very bad!

Maybe the diesel filter is clogging up - any indications as to when it was last changed?

Also the diesel return pipe, could be worth checking that out.

Have you been aware of any smoke - very unusual on HDi's unless something is awry.

steve1951 · Post by **steve1951** » 26 Sep 2009, 14:17

No sorry I didnt explain myself properly. The sound from the pump is the same a buzzing or whirring noise whether just the ignition on, whilst driving I assume and after the stall. If it was intermiitent failure the whirring would surely not be there after the car stalled. IE pump not running.

The engine management light is on. It came on at the first stall, the car stalls, and will not start until I lock and unlock the car.

Is there anything which would throw up the engeine management light and stall the car, which when I lock/unlock is overridden for a short while then fails again. ie a sensor or something like that.

steve1951 · Post by **steve1951** » 26 Sep 2009, 15:08

She does smoke a bit on start up but I assume that is valve stem seals.
Other than that have not noticed anything.

No I didnt take it right out, I assume this is the next step, but unsure how do does the black locking ring turn or clip off.

steve1951 · Post by **steve1951** » 26 Sep 2009, 15:20

Back from playing ( groans all around)

I went down to the car unlocked turned on ignition, removed the feed pipe from pump assembly. got covered in diesel. Started car did the same, same result, Removed filler cap, drove off about 3/4 mile stalled left everything the same ignition etc pulled pipe, nothing, locked and unlocked doors turned key in ignition and sprayed diesel every where.

Some electrical system connected to me locking and unlocking the door is cutting the fuel, does the immobiler cut the fuel. Is there a relay/sensor which cuts off the fuel. As already said when the stall happens the red stop lights up and one beside the temperature gauge.

I think the whirring buzzing noise I could hear is a stepper motor or something like.

I am toying with the idea of running a direct electrical feed ignition controlled to the pump, but unsure if that is safe to do

Sorry to be such a pain

steve1951 · Post by **steve1951** » 26 Sep 2009, 15:30

Sorry still trying to get my head around this hmmm rather somewhat annoying problem.

Is the low pressure pump in constant supply mode merely returning excess back to the tank, or is it switched in and out as supply demands.

KevMayer · Post by **KevMayer** » 26 Sep 2009, 19:07

Well done in finding that the fuel supply from the low pressure pump stops.

The pump should supply pressure to the HP pump all the time the ignition is on, otherwise the HP pump won't be able to work.

Post by **myglaren** » 26 Sep 2009, 19:12

Don't confuse the whirring from the suspension pump with the fuel pump.
Suspension pump is much louder and will almost always run for a few seconds on unlocking the car, then at random times thereafter.

steve1951 · Post by **steve1951** » 26 Sep 2009, 21:49

cheers Kev now all i have to do is find out why it stops. I know nought about them, would running an ignition contolled live to the pump be an option. Or is it try and get immobiliser sorted, bit expensive though.

cheers mate Steve

steve1951 · Post by **steve1951** » 26 Sep 2009, 21:53

Thanks Myglaren been at it again and yes I am convinced it was the suspension pump I heard. Sorry for the confusion.
Have already asked Kev about option of running a new feedto pump, I am fast running out of ideas now.

Post by **myglaren** » 26 Sep 2009, 22:41

steve1951 wrote:Thanks Myglaren been at it again and yes I am convinced it was the suspension pump I heard. Sorry for the confusion.
Have already asked Kev about option of running a new feedto pump, I am fast running out of ideas now.

You could run it as a test. Be sure to include a kill switch in the circuit and disengage it when your results are clear - it would bypass the fuel shutoff device that operates in the event of a collision, not to mention invalidating your insurance.

steve1951 · Post by **steve1951** » 27 Sep 2009, 00:12

Cheers again mate, will give it a try tommorow.

Steve

Post by **Paul-R** » 27 Sep 2009, 18:59

steve1951 wrote:.I am toying with the idea of running a direct electrical feed ignition controlled to the pump, but unsure if that is safe to do

That's more or less what I did with the Xsara a few years ago. I was plagued with non-starting problems - sometimes it would, sometimes it wouldn't.

The very worst time was when we were in France and couldn't get started the following morning after staying in a hotel. The fuel level was low and I thought that might have been the problem so made some three or four journeys to a fuel station 1/2 a mile away with a five litre fuel can! Eventually I gave up and called the RAC overseas service. Another hour later the chap showed up, turned the key and the car started without a problem!!!

When I got back home (the car having started perfectly the rest of the time, of course) I eventually found that there was an intermittent supply to the fuel pump. I just couldn't be ar$ed finding out why so bypassed the circuitry at the fuse box with a fused relay fed from a live source and switched by an ignition feed. It's worked perfectly like that for some 50,000 miles since then.

The one disadvantage is that there is supposed to be a safety mechanism wherebye if the engine isn't started after turing the "ignition" the feed to the fuel pump is cut after a few (5?) seconds. This is no longer available so I have to remember not to leave the ignition on.

mark21td · Post by **mark21td** » 27 Sep 2009, 21:01

I had something simaler with an 806 HDI, but it only happened when I had less than 1/2 a tank of diesel.
When the HDI's first came out PSA had a big problem with them cutting out like this and took a long time to sort it out.

xmexclusive · Post by **xmexclusive** » 27 Sep 2009, 22:44

Been scanning a few Citroen workshop manuals from a job lot I bought just to get an idea what I got. Came across a recall item for HDi diesels that required a non return valve in the tank return to be removed and replaced by a straight connector. Think the mod was to overcome engine stalling problems. Will see if I can find it again.

John

steve1951 · Post by **steve1951** » 28 Sep 2009, 02:00

Hi all thanks for the tips.

Paul-R , I wonder if this safety thing which cuts feed to pump, if engine not started after a few seconds of ignition on, could be the problem