C5 Starting Problem

Hi to all
Can anyone advise on likely causes for non start of the 2.0 HDi
I have replaced all glow plugs with new and it was working fine for several
weeks but then would not start.
It seems that if the air is very damp it won't start.
I have an electric fan heater which I put under the bonnet for about 20mins - it will start after this.
I don't think that the heater imparts enough heat to the engine to make the head warm enough to allow the engine to start - could it be that the heater dries out the air in the intake and this solves the problem?
Next stop is a new preheat control box but I am not convinced this will resolve the problem
Any help gratefully received.
Many thanks
Andrew
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
Hi Andrew If you don't find an answer in here , I suggest that you re-post the same question in, "alt.autos.peugeot" as its the same engine, the peugeot group gets a lot more postings to it.
GGJ

Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
<snip>

I am...
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
Jerry
That's pretty positive.
You wouldn't know:
a) where is the control box? - it's so complicated under there it's hard to id the engine never mind anything else b) the correct electrical output from the control box - by measurement I get 12V to the glow plugs for about 4 seconds on initial ignition switch activation dropping to 4V thereafter. I presume this voltage switches off when the engine is fully warm - can't see any reason why the glow plugs should remain powered once warm.
Thanks
Andrew

Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

Sorry for the delay, my main news server is down...
Sorry but I'm not sure where the CB is on the C5 but what I would like to point out is that you shouldn't be measuring volts but current (amps) - and you need to know how to use a amp-meter - it's not the voltage that is lacking but the if the amps are available (at the glow plug terminals) and if so, are they being used correctly or fully.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
Jerry
Thanks for the extra information - when I buy the new module, which I surely will have to, I will try and get the dealer to show me the exploded diagram of the car and hopefully this will tell me where the unit is located.
Your point about current is well made - my voltage tests were to see if the control had an output, which it does, and what that voltage output is.
The glow plug rail current, from information from this forum and by calculation is around 30 amps and I don't have a meter that will cope with this. I suppose I could check each glowplug in turn but this is a tedious exercise and would involve temporary rerouting of connections through the test meter. At a total load of 30 Amps it is not worth the effort.
I think that the control of power to glowplugs is done by voltage reduction. With the glowplug resistance being fixed the only way to control current is to adjust voltage which is what appears to be happening.
Still, as you advise, a new control box is probably in order so roll on pay day.
Andrew

Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
As far as I know, C5 does not use glow plugs unless temperature is below some minus centigrades. Therefore I think, glowplugs are not the reason for your problem. Did you check fuel pipe? My Xantia had a leak in the fuel pipe. This caused a air input over night. Pumping by manual fuel pump solved the problem temporarily.
Best regards

several
the
heater
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

Yes, that would cause problems but it would not be helped by warming the ambient air temperature in the engine compartment.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
Hello to all
My starting problem persists.
A new control box fitted yesterday (the control box is in the engine bay, underneath the ECU (right hand side of the bay as you look down on the engine standing at the front of the car) by the way) but this morning at -2 degrees C the car still won't start.
It was OK yesterday after I had fitted the module but this was mid afternoon with air temp around 12 degrees.
I could solve a lot of this by having the car on the Citroen dealers computer - this might tell me what the problem is but not at 75 quid at time plus VAT - Talk about a rip off.
Any further suggestions gratefully received
Andrew

several
the
heater
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
<snip>

Well, I'm sorry that the 'obvious' failed to cure the problem, I'm now starting (no pun intended!...) to wonder if your description of the fault is a symptom rather than the cause and that warming the ambient engine bay temperature is just coincidental IYSWIM, are there any other symptoms past or present - for example does the engine get increasingly difficult or longer to start after being left for some time even though the engine block and or ambient temperature is still reasonable? The other thing to point out regarding the cost of having the vehicle put on the dealers computer, OK 75 + VAT is a lot but you could end up spending more than that 'guessing' at what part(s) to replace next, sometimes it's actually cheaper in the long run to gulp hard and pay up - a bit like insurance in fact...
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
Thanks for taking the time to respond further.
Your point about the charge for the computer readout is well made but I have an almost pathological hatred of being, or feeling like I am being ripped off. The readers are upwards of 4K to buy. 15 cars a week on the machine at 75 each equals over 1K per week - 4 weeks and the machine is paid for, 10 weeks if it costs 10K etc. I know the maths is not as simple as this and I know that not all garages charge in this way but this Garage would not even guarantee that the computer reader would tell me what was wrong - ergo, potentially 75.00 down the tubes for no certain result. What they are probably angling for is for me to leave the car with them, probably to the tune of 300+ including the computer test - sorry to rant but it is irritating - bring back the A series, I could figure than one out with a big hammer!!!
To the fault.
I have not had this car a year yet and it has been very good. This problem only occurs in very cold weather and apart from one occasion late last year only in the mornings. In order to get to work I put the fan heater under the bonnet and turn it on when I get up. The 3 S's, get dressed, turn of the fan heater and start the car - bingo every time.
So far, apart from one or two occasions when very very cold it always start in the evening on the way home.
On those occasions I tried the old trick, turn over for 10s, wait for 60s, turn for 10s wait for 60s, repeat a number of times and the engine starts. The waiting is to give the battery time to recover (slightly) and to allow heat generated in the attempted start to dissipate into the block. The process is supposed to warm the head enough to get the engine to fire.
Back to the problem.
The starting in the morning only gets tested on Saturday and Sunday - all other times I need it to be reliable so use the fan heater. I replaced the glow plug control module on Saturday and it started ok afterwards
This morning I when down at 9:00 and it would not start (sob sob as was expecting it to) 1/2 hour with the heater and off she goes. I did not drive it and left it running for only about 5 minutes while I looked around under the bonnet for inspiration. I have left it all day since about 09:30 till a few minutes ago, went back out and tried to start it and it starts first time. The block must have cooled by now and yet it starts OK - although the ambient temp is again around 12 degrees C.
I have found an air temperature sensor (in the same module as an air flow sensor) in the air intake line and I wonder if this is reporting wrong. It measures around 3.8K at 12 degrees C and if I warm it between my fingers this reduces to 1.8K. I have no way of telling what these values should be but this could be the cause of my problem?? - looks expensive though.
To answer your question, no problems with starting other than when very cold. No progressive starting difficulties. It seems that it is most likely to not start when left standing overnight and when very cold.
Thanks for your help so far
Andrew
Thus the only time

Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

I know what you mean, well remember hearing all sorts of 'get you home stories' about the A series and Morris Minors, although the later BL A+ engines had their own fables but we digress...

<read but snipped>
Just a hunch, when was the fuel filter last changed, this being the weak link in any diesel fuel system [1], just wondering if there is muck that is (in effect) waxing the filter up in cold weather? As for the sensor, yes it's possible but I don't know the correct values off hand either, perhaps Adrian will pick up on your message and know (via his contacts in the Citroen UK club) were to obtain get them.
[1] also changing the filter and then re-priming the system can show up other faults with the fuel line / lift pump.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
Jerry
Thanks again for showing an interest - car has been fine all day, starting quickly every time - just would not start after the night standing in the cold.
Fuel filter is a very good idea.
Any idea where it is - again so complicated under there its hard to tell what's what. I have found the water bleed pipe - small blue cap on top of what looks like a container that could be the fuel filter. I don't want to mess about too much in this area because of the high pressure rail. If this is running at 20K+ psi any leaks could take your head off.
Something that someone else mentioned. When the car finally starts, like this morning, only after I put the electric heater under for about 20 mins, I get a fair amount of black smoke from the exhaust. This other contributor suggests this means fuel is getting through which makes sense.
Any thoughts?
Andrew

Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

Related Threads

    Motorsforum.com is a website by car enthusiasts for car enthusiasts. It is not affiliated with any of the car or spare part manufacturers or car dealers discussed here. All logos and trade names are the property of their respective owners.