Simon's new Xantia V6 and Leaf blog

[Mandrake]

I think that the plastic degassing tanks (1307HJ) are being remanufactured now, but a quick search does not find them. I have a spare used one (in good condition) that you can have, but I can't get it to you until the beginning of May, as it is in France and I am in New Zealand.

I need to start getting it ready for the WOF by June so that would be cutting it quite fine. I don't know what other work the car is going to need, or whether I can solve the ignition cutout problem, and I can't really test that until I fix the coolant leak.

A bit of Googling tonight has turned up this - it looks promising I think, and the angles look correct for the Xantia ? Is 11mm for the upper connector correct ? (I think the Peugeot version is much larger diameter ?)

https://www.cx-basis.de/dampfblasenabsc ... 20726.html

Please, nobody buy one in case they have low stock. Not until I have one safely in my hands at least.

For your fault codes, I would try cleaning all of the wiring connectors that you can find in the engine bay and ECU box.

I've done that already a few months ago including the ECU connectors, (engine ECU as well as the gearbox ECU) the connector on the coil pack and the one that lives on the side of the inlet manifold near the fuel pressure vacuum hose. No real change. (Although cleaning the gearbox ECU connector which WAS a little corroded seems to have solved some cantankerous gearbox behaviour)

[Mandrake]

The coil pack is a good call for all the ignition issues Simon. I had two fail on me when I ran V6s... They are not the most reliable bit of the V6.

Certainly the first thing to eliminate.

If I had a new or known good one I would swap it in a heart beat, the problem is the one I have spare was bought new however was only on the car for a few months but was swapped again because I thought it was causing intermittent misfire issues. Maybe that problem was really something else, I'm not sure.

I think the one on the car now is Sagem and the other one I have is NGK.

I guess I will swap it anyway and try it, however I really have to replace the swirl pot first as I can't drive the car like that. I also really need to do the coolant level sensor wiring "fix" so that the coolant warning actually works!

It makes me incredibly angry that they went to the trouble of fitting the sensor and running a cable to it, that only has ground and power and no signal...

Has anyone documented the process of hooking up this third wire to make the sensor work, hopefully with some pictures ? I feel like I really need it working because had I driven long distances with such low coolant levels I could have easily cooked the head gaskets and effectively written off the car... (if they haven't already been damaged!)

If I can't fully trust the cooling system even after this repair I should at least have a working low coolant warning light, that would give me peace of mind.

[xantia_v6]

Re the coolant level sensor:

I did not take pictures, but it is the wire to pin 6 on the bitron box, should be labelled 405 and is probably white.

[Mandrake]

Re the coolant level sensor:

I did not take pictures, but it is the wire to pin 6 on the bitron box, should be labelled 405 and is probably white.

Does it not need a diode to isolate it from the other signal that can bring the coolant warning light on ?

[Mandrake]

A bit of Googling tonight has turned up this - it looks promising I think, and the angles look correct for the Xantia ? Is 11mm for the upper connector correct ? (I think the Peugeot version is much larger diameter ?)

https://www.cx-basis.de/dampfblasenabsc ... 20726.html

Please, nobody buy one in case they have low stock. Not until I have one safely in my hands at least.

I decided to go ahead and order this - 20 euros for shipping so all up around £50, I guess that's OK for a replica of a part that's extremely hard to find!

Any tricks to fitting it or is it pretty straight forward ? Is it bolted to the engine somehow or does it just hang on the rubber hoses ? Am I going to need to take the upper inlet manifold off to get enough access to fit it ?

If so I'll need to order some more paper gaskets as I don't think I have any left. Will also need coolant as I'm going to lose a lot removing it and might as well do a full coolant drain and change as part of the job.

[xantia_v6]

No diode needed (none on the other models that use the same components). The signal wire to the warning light is grounded by the level sensor or Bitron, or both.

These are the hj coded parts, nearly new and old....the OP image is not for certain...fitted and the matching expansion tank (for the Xantia)

Do your rubber pipes match those shown ?

The middle image shows one end of the spring clip that holds the degassing tank.

[Zelandeth]

Something I'd take a look at through the real-time data when you're back up and running is the ignition timing.

Something I've seen on Saabs is dodgy knock sensors (or wiring to them) causing the engine management to throw a major panic because it thinks the engine is knocking and waaaaaay retarding the timing in response.

Not sure if this is something which happens on Citroens but could be worth looking at.

[xantia_v6]

I have had a Xantia V6 misfire caused by oil flooding in the spark plug wells. I don't remember any codes from that.

[Rp0thejester]

I would like for you all to realise what time it is!! If Matron catches you your in trouble!!!

[Armidillo]

I would like for you all to realise what time it is!! If Matron catches you your in trouble!!!

Mike & I are allowed out of bed because we're in the Southern Hemisphere.

Simon, so sorry to hear that you are having so much trouble. I'm following your story with interest, as I have an XM with the same engine.

Oil in the plug wells can be from camboxes leaking, but if it's in the front wells it can be from the filler cap. Have had this problem with both XM and 406. I have managed to replace the standard cap seal with a couple of O rings - use one that fits snugly around the centre part of the cap, then another that has a larger diameter and fits around the outside of the first O ring.

[Mandrake]

These are the hj coded parts, nearly new and old....the OP image is not for certain...fitted and the matching expansion tank (for the Xantia)

Do your rubber pipes match those shown ?

The middle image shows one end of the spring clip that holds the degassing tank.

The replica I've ordered shows some kind of clamp around the middle - whether that's actually holding the two halves together I don't know, but I presume it will fit the spring clamp that is attached to the motor....

Given how impossible the original is to find I guess I'll just have to make it fit.

[Mandrake]

Something I'd take a look at through the real-time data when you're back up and running is the ignition timing.

Something I've seen on Saabs is dodgy knock sensors (or wiring to them) causing the engine management to throw a major panic because it thinks the engine is knocking and waaaaaay retarding the timing in response.

Not sure if this is something which happens on Citroens but could be worth looking at.

Both my Xantia V6's have had what I believe to be unintentional triggering of the knock sensor due to clattering hydraulic lifters.

I believe under certain circumstances - such as when the lifters are not pressurising properly (ticking tappets) the mechanical clatter triggers the knock sensor, pulls back the timing and kills the performance.

When this happens there is a very sudden "surge" of acceleration when you exceed 4000 rpm because the knock sensor is not used (or not used as much) above 4000rpm.

This surge is not normal and indicates triggering of the knock sensor.

I've spent countless hours troubleshooting this issue across both cars and spent many pages of forum thread discussing it.

At one point I actually connected an attenuator to the knock sensor to attenuate the electrical signal slightly - and I was able to confirm that this did indeed mostly eliminate the performance loss, however I was uncomfortable leaving this in permanently in case it was desensitising the sensor too much.

In the end I just switched to a thicker oil - 10w-40 instead of 5w-40, and this seems to be enough to allow the slightly worn hydraulic lifters to pressurise properly, keeping them quiet most of the time and the loss of power below 4000rpm doesn't seem to happen anymore.

My feeling is that the knock sensor on the ES9J4 IS too sensitive, and is easily triggered by excess mechanical clatter in the engine - and when the lifters get worn and leaky and start having trouble pressurising properly the mechanical clatter from them is enough to start triggering the knock sensor when it shouldn't be.

The problem I've experienced recently is something else though - it is a massive power loss to the point where pulling away from a junction is difficult, it does sound and feel like a loss of two cylinders and that could be consistent with one of the coil primaries going open circuit as reported by the Lexia, since that will take out two cylinders.

[Mandrake]

I have had a Xantia V6 misfire caused by oil flooding in the spark plug wells. I don't remember any codes from that.

While I haven't checked it recently, I have had the intake manifold off this engine two or three times since I've had the car - including when I fitted a new rear bank spark plug cassette and unlike my first V6 that had major oil leaks in the spark plug well area this one was absolutely dry with no leaks.

If I can find some gaskets for the intake manifold I may remove it when I fit the degasser to make that job easier - and check the spark plug wells at the same time. I'm not sure what I would do if I did find a major leak though.

[Mandrake]

I did a search and found I still have one new unused manifold gasket and one that has been on the car but still looks nearly new - I vaguely remember that I fitted one and had to take the manifold off again a couple of days later so I fitted another new gasket and kept the one that had only been on for a couple of days. So I'm OK for gaskets.

I also found the spare coil packs I have - all three of them!

All of them are second hand Sagem types. I believe one is from my original Xantia V6, one is the original from this V6 and the third is.... ??

All three of them look old and have cracks in the epoxy and on two of them I have previously tried to seal the cracks with big blobs of epoxy glue.

So it looks like the NGK coil pack is the one that is actually on the car - that was fitted new maybe 5-8 years ago.

I'm not sure which of these three coil packs is which because none of them are labelled and at least one of them has a fault when it heats up so I don't really have a good trustworthy substitute at the moment, other than for testing purposes. It would probably take quite a bit of test driving to identify if any of the three coil packs is reliable when hot.

New coil packs are still available from Autodoc from around 10 different manufacturers ranging from about £80 to £200 with most well known name brands like Valeo around £145....

https://www.autodoc.co.uk/car-parts/ign ... -3-0-i-24v

[CitroJim]

Most V6 Coils have cracks Simon, and often not anything to worry about...

Watching this with great interest... It never occurred to me that rattly tappets could set off the knock sensor but it makes perfect sense!