The C5 Woes Begin.

[falling-out-with-my-car]

Hi, as for reliability My 2007 16 Valve exclusive HDi has been marvellous
ever since the day I bought it, until last night.

I did my usual stint looking after family and left their house late to drive to Kettering
to do some shopping, I sat in the car with the engine running for about 20 minutes
listening to the radio and answering some messages on my mobile phone.

turned the engine off set the alarm went and did my shopping and when I came back the engine fired but immediately stalled then
refused to start again.

I must have cranked the engine about six times before lifting the bonnet.
I wriggled the airflow sensor wires on the air intake pipe behind the air filter because that's something I had to remove recently to remove the
air filter housing to change the filter.

I also noticed about a six inch bubble in the clear fuel line that runs over the top of the engine.
I flicked this clear pipe couple of times then
I closed the bonnet I checked the display screen inside the car for faults and there were none.

then I tried cranking the engine and she fired up, I then drove about 20 miles up and down the A14.
before coming home.

any ideas please?

Do these suffer from glow plug failure like the xantias do ?
and is it a fairly simple job to replace the fuel line?
There was no smell of fuel whilst cranking the engine which I thought a little strange if there was a leak in the fuel line.

I have noticed with the engine idling that the engine shudders occasionally just a little almost as though it is being fed air instead of fuel.

you can feel this inside the car.

thanks in advance.

Nigel

PS. after a reset the service light problem I had turned out to be a warning that the tyre pressure sensors were not being monitored
the service light was lighting up on its own when I first got the car but now I get the tyre pressure warning on the screen at the same time
and the service light goes out shortly afterwards and stays out.

[GiveMeABreak]

Well there is obviously some air getting into the fuel line somewhere. With the HDis, the fuel is compressed to almost a vapour, so when air gets in, the gas will compress, where the fuel being a liquid almost won't, and the pump can't then build up enough pressure in between the injection cycles, so not enough fuel gets in and it stalls.

Sometimes the O rings in the diesel fuel filter may not be sealing. Have you replaced the diesel fuel filter lately? - Might be worth checking the seal out there first.

[falling-out-with-my-car]

My first service was done at Pleiades 2500 miles ago new filters and oil change.
I remember the housing lid being very very tight and difficult to turn to release.
there was a minor bubble in the clear section of the fuel line when I bought the car.
but it seems to have grown.

strange Ive just been out and started the car first turn of the key, I lifted the bonnet and checked for air
in the clear fuel line there is one small bubble at the peak of the cam housing.

I may have been mistaken about the size of the air bubbles using a torch in the dark.

could this be a power issue perhaps not enough amps in the battery to heat the glow plugs?

ive been doing short distances of about a two miles a day lights on for about a week.

when this happens I usually go for a 40 mile drive once a week in fourth gear at 70mph 3000 rpm

for the sake of the depollution system on the exhaust.

Nigel.

[GiveMeABreak]

I've heard all extremes of how air can get into the fuel system - including flatulent algae in the fuel tank!

[CitroJim]

HDis generally do not need glowplugs to start unless it is *very* cold indeed.

They do post-heat once started but only as an aid to emissions and smooth running.

Air is a possibility but it may too be a lack of fuel pressure - A Lexia session may show some clues when it happens, maybe showing low fuel pressure somewhere or even a duff signal from the cam position sensor or such-like..

[GiveMeABreak]

There's an interesting PDF article on the problem here:
Mobile_Air_Separation_In_Diesel_Fuel

[RichardW]

Well there is obviously some air getting into the fuel line somewhere. With the HDis, the fuel is compressed to almost a vapour, so when air gets in, the gas will compress, where the fuel being a liquid almost won't, and the pump can't then build up enough pressure in between the injection cycles, so not enough fuel gets in and it stalls.

Er, no.... you can't compress something 'almost to a vapour' - it goes the other way; compress a vapour enough and it will condense into a liquid (although I see perhaps what you are getting at - when the fuel is at very high pressure it generates a very fine mist of diesel when injected into the cylinder, which is a bit like vapour and burns more easily). The HDi relies on there being no gas in the rail or pump so that the diesel can be pumped up to very high pressure very quickly (liquids being almost incompressible). If there's air in the pump then it won't be able to do it. Sounds like an air leak to me - if it does it again, then try pumping the primer. Won't be the glow plugs as these DI engines will start without unless it is very cold.

[GiveMeABreak]

(although I see perhaps what you are getting at - when the fuel is at very high pressure it generates a very fine mist of diesel when injected into the cylinder, which is a bit like vapour and burns more easily).

That's exactly what I was referring to Richard.

[falling-out-with-my-car]

strange Ive just been out and started the car first turn of the key, I lifted the bonnet and checked for air
in the clear fuel line there is one small bubble at the peak of the cam housing.

I may have been mistaken about the size of the air bubbles using a torch in the dark.

could this be a power issue perhaps?

ive been doing short distances of about a two miles a day lights on for about a week.

when this happens I usually go for a 40 mile drive once a week in fourth gear at 70mph 3000 rpm

for the sake of the depollution system on the exhaust.

Nigel.

[falling-out-with-my-car]

ahh 10 year old leaky primer bulb more like.

isn't the primer bulb on the low pressure side of the fuel pump?

Nigel

[falling-out-with-my-car]

There's an interesting PDF article on the problem here:
Mobile_Air_Separation_In_Diesel_Fuel

Thanks Marc, an interesting read,

Interrupted exhaust beat seems to be exactly what is going on occasionally
this shakes the whole car but its not every day that it happens only after a long period of idling the engine
20 mins or more.

Nigel