I have posted several queries about this car (citroen xsara 2.0. hdi 2001 {added to subject header - DD}) and followed advice given I think I am close to solving it. cleaned engine bay, jet wahed engine, secured oil filler cap all as previously advised now can see where oil is coming from took injectors out this weekend and they are coated with engine oil they have copper washers at the seat end, and rubber/plastic
collars at the top end do these act as seals that could be worn? now that I can see the cleaned engine after a short drive of about 10 miles there is evidence of oil in the valleys of the cylinder head casting where the injectors fit and upon removing them I found the oil on them as previously stated What is going on here??????
|
wrigley
The very fact that you could remove them shows that their seating washers are leaking oily combustion residue. It's not unusual and often ignored; but if it's causing a problem, just clean the seats in the head and replace the copper washers. They're one-shot-use anyway.
Don't forget that having disconnected the injector pipes they too MUST be replaced, every time, as they have crush-sealing ends. Needle-fine, near invisible, jets of diesel at 20,000 psi from a leaking union are fatal.
|
thanks screwloose,
you have my full attention, must be the word FATAL!!! could you explain in more detail for me why being able to remove them indicated such a fault? also I see the copper washers you are on about, can I buy them from a citroen dealer and are the plastic collars at the top of the injectors replaceable to, also the injector pipes are they in a set and what precautions do I need to take when changing them given that the engine will not be running, also any idea of cost.
p.s. how do you clean the seats as they are at the bottom of a 4/5 inch hole.
thanks in grateful anticipation wrigley
|
wrigley
It's becoming fairly plain that information that quickly disseminated through the trade in regard to the extreme dangers of common-rails hasn't percolated into the DIY world.
Leaking diesel unions are nothing new. The difference with constant-pressure common-rail and the previously "pulsed" pump-to-injector pipes is that a leak is no longer, visibly and audibly, "puffing" or dripping and can thus be an virtually invisible constant needle-jet. [At that pressure it will instantly penetrate your flesh and enter your bloodsteam at ten feet or more. Hearts won't run on diesel - you won't even make it to the hospital.]
All common-rail pipes have compression-seal ends and must be discarded on removal. Although they will often appear to re-seat; the risk exists that the seal may not hold and the consequences of a leak are so serious that only replacement with new is allowed.
Before starting the engine after pipe replacement, a clean sheet of paper is laid across the injectors/pipes and the bonnet is closed. The car is run for a short while and then switched off. The paper is then examined for traces of diesel. You never check for a common-rail leak with your eyes - it may find them, not the other way around.
As far as HDi injector removal goes; they're usually stuck fast into the head by a substance closely resembling resinous coal. Only if there's a significant oily leak are they free to withdraw. The cleaning tool should be available through the dealer's parts dept. along with the washers and pipe set. A Haynes manual would be another wise purchase.
|
[At that pressure it will instantly penetrate your flesh and enter your bloodsteam at ten feet or more. Hearts won't run on diesel - you won't even make it to the hospital.]
Blimey, I didn't know it was that powerful... :-o
|
me neither.
I have ordered the parts now so can you put me right as long as the engine is not running and therefore the injection pump not operating it is safe to undo the injector pipe unions as they are not pressurised
|
wrigley
The pressure regulation solenoid opens and dumps the rail pressure at key-off.
The engine will not stop until the ECU sees pressure in the rail drop to a safe level. Wait five minutes after the engine has stopped before opening any union. See the Haynes manual for a full rundown on all the safety precautions.
|
screwloose,
thanks for that I have tried to purchase a haynes manual already but without sucess they do one for the xsara picasso or the xsara saloon up to 2000 acording to their website but not for the later hdi engine models if you have any different information regarding how to obtain one please let me know
I really would like to refer to one now that you have highlighted the potential dangers.
thanks alot
|
|
|
|
[At that pressure it will instantly penetrate your flesh and enter your bloodsteam at ten feet or more. Hearts won't run on diesel - you won't even make it to the hospital.]
10 feet? nope. fluid patterns and droplet dispersal will ensure that anything over three feet is nothing less than a wet arm. Does not matter how high the pressure, or what the fluid is, it wont be sufficient to pierce skin.
It would however be enough to spray into your eye, rather nasty in itself. Probably the spray would be dispersed enough to ingest as mist, again rather nasty.
------------------------------
TourVanMan TM < Ex RF >
|
|
|
|
|
Don't forget that having disconnected the injector pipes they too MUST be replaced every time as they have crush-sealing ends. Needle-fine near invisible jets of diesel at 20 000 psi from a leaking union are fatal.
You have put the wind up me as I didn't know this..... :-o
my van is not common rail thankfully, but is there any danger of leaks occurring in the normal course of events or only after injector removal. Is this why newish cars have a plastic shield covering up the engine?
----------------------------------------------
One mans junk is another mans treasure
|
Steptoe
Leaks were never a serious issue with non common-rail systems as there's not a constant pressure in the injector pipes. Any leaks, big enough to be harmful, were pulsing on and off. A common-rail can produce a constant jet from it's reservoir of pressurized diesel.
Yes; that's one reason why common-rails have shields.
|
|
Slightly OT but its worth mentioning. Never unplug an injector on a HDI with the engine running, it will put a conrod through the block in a couple of seconds. The should not be steam cleaned for the same reasons in case water gets into the electrical connections
|
At one stage in my working life I used to work on steam boilers which typically they would operate around 120psi. Nasty if you got in the way of it.
This thread reminds me of some guys I once worked with who had worked on superheated steam or dry steam as its sometimes called.
The pressure were very high but nothing like the 20,000 in CR systems.
They told me of the inherent danger when checking for leaks on pipework.
They used some kind of shield when checking and said that a jet of leaking steam (invisible of course) at these pressures would pass right through your hand.
Don't know if this was factual or not but they sounded convincing.
wemyss
|
wemyss
Given that water-jet at that sort of pressure will cut anything from concrete to tree roots; it doesn't seem unlikely.
There have been warnings that CR leaks can cut off fingers; [OK, not at ten feet; that's just the safety zone] but I've not seen any stump-handed techs - yet. [I do know of a couple of one-armed autoelectricians; but that was hydrofluoric acid...]
|
The danger from a high pressure system like this isn't a stream of fluid that cuts - I doubt anywhere near enough oil can be supplied at that sort of pressure to made it effective. The issue is from hypodermic injection of oil, although I personally think you'd need to have your hand practically against the end of the injector for this to work. Remember it's designed to deliver a spray pattern into the cylinder.
This sort of injury from high pressure hydraulic hoses has been around for a looooooong time, and I've never heard of anyone dying from it. Diesel in the body might be nasty, but I doubt it would kill you unless you got a really significant dose, which you wouldn't, 'cos it would hurt if you put your hand over the injector.
Screwloose - I know hydrofluoric acid is v. v. v. nasty stuff, but do people really lose limbs that regularly?
|
David
As you say; the previous danger was only from the injector's spray tip. The new situation, is that a fine, continuous, jet can come from a leaking union [or anywhere else on the pressure-filled rail.]
As I said; I've not - yet - seen any fingers running loose in a workshop; but the risk does, apparently, exist.
HF acid oozes from melted wiring looms; a moments inattention - often in the dark, under a dash etc. and it's on/through your skin..... When repairing such loom fires, your hands are always itching from traces of the stuff; but it's whole droplets formed at the bottom of loops that are the real danger.
Amputation at the shoulder is the only treatment. It's not exactly a regular occurrence; but in a fairly specialized trade, you do get to hear of it.
|
Extract from. tinyurl.com/2p26ql Diesel Bobs site.
VERY IMPORTANT NOTE
Common rail injection systems deliver over 200bar of pressure even at cranking speeds.
Never employ the testing methods used with conventional diesel injection systems e.g. Placing a finger over a pipe to check for pressure.
If fuel does come into contact with the skin at these pressures it will easily cut a hole through the flesh (and bone if in the way) and poison the blood resulting in blood poisoning, loss of limb, coma or even death.
PLEASE BE AWARE OF THIS FACT
PU
|
I have been sufficiently alarmed by previous posts mainly screwloose to follow the advice and have ordered the components injector pipes etc,here tomorrow cost £50 to basically replace 4 copper sealing washers ( no wonder most people leave the job unattended) however reading other posts and even the the guy at citroen said they dont always change them but there is the riisk of a leak if not resulting in loss of diesel and a breakdown was how he put it. which seems more acurate than diy people dont touch common rail or you DIE that was my feeling after reading early posts, This is a great site with access to trades people with invaluable knowledge for guys like me who are capeable of carring out repairs but just need pointing in the right direction I will certainly come back again. but please a little less drama please it reminds me of the guy in dads army you know the one
were all doooomed .
thanks a lot guys back soon
|
|
|
