Xantia V6 broken exhaust (update: and rough low rpm running)

[Mandrake]

I know what you're saying. Exhaust is going to be very expensive to fix so if I do that first everything else will have to wait for next month. The problem is finding someone to do it that isn't just going to want to replace the cat for hundreds of pounds, and trying to get time off work to get the work done. (Its almost impossible for me to get time off work with less than 2 weeks notice which is a royal PITA for trying to organise work to be done on the car)

On the other hand if it breaks again I'm stranded, so it does need sorting soon. No hints anyone of a good independent exhaust fabricator in my area who would tackle fabricating a new sleeve for the cat tail ?

[addo]

The catch there, is good "independent motor engineers" are usually well booked up. Would any of the forums like Autoshite or Practical classics be able to help?

Exhaust fitting is a lifestage between incarceration and reintegration, and thus the people you meet working in such a domain are frequently both criminal and maladjusted - hence the attitude and pricing.

[RichardW]

Exhaust fitting is a lifestage between incarceration and reintegration, and thus the people you meet working in such a domain are frequently both criminal and maladjusted - hence the attitude and pricing.

thanks for brightening my day up!

Simon - if the cat tail pipe is essentially sound, and that clamp arrangement you posted up on the bay is available in (approximately) the right size, I 'm sure I can weld it together. You'd either need to come down and strip it off the car at mine, or bring it on the train Friday afternoons or weekends, generally, but I could do it in an evening if you bring the cat down.

[addo]

You will need a specialist Doctor's letter to take your cat on a train (companion animal, Asperger's should do it). It will need to be in a covered cage.

[Mandrake]

Thanks Richard, that would be a tremendous help. Those fittings on eBay come in several sizes, inside diameter of 45, 50, 55, and 60mm with all but the 45 saying Xantia.

Anyone know the diameter of the cat tail ? Like a fool I didn't measure mine when I had it apart!

They're cheap enough that I could get more than one size to give us maximum flexibilty I guess. Will order them today if I can find the right size.

Are we sure they're steel and not aluminium ?

[CitroJim]

Adam, I LOL'd a lot at your comments Will ME do as a qualifying condition.

Most engineers hate exhaust work. I do certainly.

Simon, I have a spare cat here and will go and measure it in a bit for you. Do you prefer inches or those funny metric measurements? Being a Kiwi I'm not sure what your preferred choice is...

Back along I spoke about the charcoal canister. It's not the idle valve. If you look at a small hose that comes out of the throttle body it goes off to a valve mounted on the slam panel and then the pipe disappears off under the nearside wing. It ends up in the charcoal canister whose function is to collect vapours from the fuel tank and recycle them through the engine. You can test the purge valve with the Lexia and it should click. However, if you disconnect the pipe at the purge valve you can block it off to exonerate any problems there.

A good test of airtightness of the inlet tract is to slip off the airbox, idle the engine and then clamp the palm of your hand across the smaller of the two pipes going to the airbox; the smaller one is idle air only so if you block it you should be able to stall the engine. If it won't stall then you have an air leak.

Also, whilst the airbox is off, check the crankcase breater pipes and the pipes that allow the camboxes to breathe. These all end up in the inlet tract and could be a cause of air leaks.

I'll be back with the cat tail measurements later...

[Mandrake]

Simon, I have a spare cat here and will go and measure it in a bit for you. Do you prefer inches or those funny metric measurements? Being a Kiwi I'm not sure what your preferred choice is...

Ah, that would be brilliant I've got a feeling it will be around 55-60mm but I didn't measure mine and its impossible to measure without pulling it all apart...

Funny metric measurements please. Kiwi-land has been metric for everything since 1967, including kilometres per hour... Imperial measurements including mph are something of a throwback for me, given we switched to metric before I was born.

Back along I spoke about the charcoal canister. It's not the idle valve. If you look at a small hose that comes out of the throttle body it goes off to a valve mounted on the slam panel and then the pipe disappears off under the nearside wing. It ends up in the charcoal canister whose function is to collect vapours from the fuel tank and recycle them through the engine. You can test the purge valve with the Lexia and it should click. However, if you disconnect the pipe at the purge valve you can block it off to exonerate any problems there.

A good test of airtightness of the inlet tract is to slip off the airbox, idle the engine and then clamp the palm of your hand across the smaller of the two pipes going to the airbox; the smaller one is idle air only so if you block it you should be able to stall the engine. If it won't stall then you have an air leak.

Also, whilst the airbox is off, check the crankcase breater pipes and the pipes that allow the camboxes to breathe. These all end up in the inlet tract and could be a cause of air leaks.

Thanks, I'll check some of these pipes etc as soon as I get a chance, not sure when that will be with it being pitch black when I get home now and constant rain. I'm working on Saturday and going to visit homer jw on Sunday to put the Lexia on his C5 to see if we can bring his gearbox back to life and out of limp home mode, but I may get a chance depending on how long that takes.

[CitroJim]

Simon, here's the critical dimensions and a picture of a good cat tail.. And as requested in funny metric measurements You and your neighbouring Island (Addo-Land) must have gone metric at about the same time then. Bet you find our half and half approach to it a bit odd...



End diameter: 61mm

Distance from end of pipe to trailing edge of roll section (the double skinned section): 32.5mm

Maximum diameter of the roll: 78mm

The double-skinned section does not need to be there and the metal of the tail is thick enough to have a fabricated roll section welded on to it. The roll section is essential to allow the bell-end of the mid section to sit snugly against it and thus form an effective seal with a clamp around it.

Be interested to hear of your adventures with Homer's gearbox. AL4 or HP20?

[Mandrake]

Simon, here's the critical dimensions and a picture of a good cat tail.. And as requested in funny metric measurements You and your neighbouring Island (Addo-Land) must have gone metric at about the same time then. Bet you find our half and half approach to it a bit odd...

Yeah it is odd to have mph for road signs, MPG for fuel consumption, yet petrol metred in litres at the pump. Also having a mixture of units elsewhere like food and weights and measures.... crazy.

End diameter: 61mm

Blast and botheration. The largest size fitting on offer is 60mm inside diameter, so it won't fit. What do you think Richard ? Would cutting a slit to allow it to fit over and welding the slit shut do the trick or is it likely to be a disaster...I suppose at £10 and £4 p-p I don't have much to loose in ordering them to see what they look like in person. Maybe they are slightly larger than stated, otherwise what model of Xantia would 60mm fit ?

I'm still not sure whether those are actually steel and not something else like alloy... maybe stainless steel. Can anyone tell from the pictures ?

http://www.ebay.co.uk/itm/Renault-Peuge ... 5791569%26" onclick="window.open(this.href);return false;

Be interested to hear of your adventures with Homer's gearbox. AL4 or HP20?

I don't know - if I knew the VIN number I could look it up in my Citroen service data but I guess it doesn't really matter, I'll find out on Sunday when we hook up the Lexia! (It never even occurred to me that it might have the same gearbox as my Xantia...)

Expect to see some posts in his thread around mid day Sunday listing fault codes found:

http://www.frenchcarforum.co.uk/forum/v ... =3&t=41417" onclick="window.open(this.href);return false;

[CitroJim]

What is crazy is equating 60mm to 2.36 inches. Inch measurements are always expressed as fractions. Makes much more sense to say 2 and 3/8"...

You might be OK with 60mm Internal diameter Simon as sizes are nominal. In fact the 61mm I measured is a tad generous. It's more like 60.7mm. I took it out to a round number. I'll bet 60mm will be a good fit. If need be, just slit it and weld up along the slit.

That repair kit on ebay is just what you want and if not quite right I'm sure it's amenable to modification. It'll be mild steel for sure, maybe plated but nothing exotic as it's too cheap...

It's an AL4 gearbox Simon. I have the training notes for those too although no direct experience of them..

[Mandrake]

What is crazy is equating 60mm to 2.36 inches. Inch measurements are always expressed as fractions. Makes much more sense to say 2 and 3/8"...

You might be OK with 60mm Internal diameter Simon as sizes are nominal. In fact the 61mm I measured is a tad generous. It's more like 60.7mm. I took it out to a round number. I'll bet 60mm will be a good fit. If need be, just slit it and weld up along the slit.

That repair kit on ebay is just what you want and if not quite right I'm sure it's amenable to modification. It'll be mild steel for sure, maybe plated but nothing exotic as it's too cheap...

I'll go ahead and get the 60mm one then... I wonder if its worth getting a couple pairs if some hacking and modification is required in case we run into any trouble and need to redo any of it. They're certainly cheap enough.

It's an AL4 gearbox Simon. I have the training notes for those too although no direct experience of them..

Do you know if there is a resettable oil wear counter in the AL4 that might throw it into limp home mode, or is it going to be something more serious such as no power to the ECU, ECU failure or major mechanical/hydraulic failure in the gearbox ? In other words could there be anything non catastrophic inducing limp home mode...

[CitroJim]

Do you know if there is a resettable oil wear counter in the AL4 that might throw it into limp home mode, or is it going to be something more serious such as no power to the ECU, ECU failure or major mechanical/hydraulic failure in the gearbox ? In other words could there be anything non catastrophic inducing limp home mode...

Yes, there is Simon.

A common fault on the AL4 seems to be the gear position switch. It gets a little out of alignment or else the internal tracks get dirty and short.

Catastrophic failure does not necessarily put the lights on; they only come on if the ECU can't make sense of what the gearbox is telling it...

[Mandrake]

Do you know if there is a resettable oil wear counter in the AL4 that might throw it into limp home mode, or is it going to be something more serious such as no power to the ECU, ECU failure or major mechanical/hydraulic failure in the gearbox ? In other words could there be anything non catastrophic inducing limp home mode...

Yes, there is Simon.

A common fault on the AL4 seems to be the gear position switch. It gets a little out of alignment or else the internal tracks get dirty and short.

Catastrophic failure does not necessarily put the lights on; they only come on if the ECU can't make sense of what the gearbox is telling it...

I read through the training manual last night, and yes there is an "old oil" counter that needs resetting after every oil change, and yes, the old oil counter getting too high will cause the warning light (snow and sport together) to flash on the dashboard, however it doesn't say whether the old oil counter will put you into limp home mode or not, I suspect not, it seems a bit drastic when its not an actual fault as such.

By the way when driving home tonight I gave it a whirl in sport mode and realised that the quality of the gear changes is MUCH smoother than it used to be.

While it hasn't done anything for the low speed rough running problem that I'm chasing in this thread, (which does seem to be an engine problem in hindsight) the actual gear changes are very smooth now, no snatch at all whether changing up or down, light load or heavy, in fact even the shift from 2nd to 1st in sport mode which produced a large abrupt lurch before is just a small fairly smooth lurch now. (And is the only type of gear change that lurches at all) So it looks like resetting the auto adaptives has really helped the gear change quality.

As I suspected, the gearbox has probably changed its tolerances significantly over the years, potentially it might have been 14 years since the auto adaptive parameters were last reset...(pity there is no way to check)

The changes were quite rough for the first half hour of so after resetting, but its taken a few days of intermittent driving for it to fully adapt and reach the level of smoothness that it has now.

So I would say the auto adaptive reset is well worth trying for any HP20 where the gear changes don't seem as smooth as they should be.

Also, the car was feeling quite zippy again tonight in cold but dry air. Whatever this engine fault is, it does seem intermittent, and does seem worse in very damp air and better in dry air...

[Mandrake]

Simon - if the cat tail pipe is essentially sound, and that clamp arrangement you posted up on the bay is available in (approximately) the right size, I 'm sure I can weld it together. You'd either need to come down and strip it off the car at mine, or bring it on the train Friday afternoons or weekends, generally, but I could do it in an evening if you bring the cat down.

Hi Richard,

Thanks for the offer, much appreciated. I've ordered the 60mm version of the clamp, (I ordered two pairs actually just in case) is there any chance we might be able to look at it next Saturday or Sunday (27/28) ? The estimated delivery date of the clamps is between the 24th and the 30th, so they may or may not arrive in time, but there is a reasonable chance they will.

Do you have anywhere out of the rain to work on the car ? I have some ramps that give just enough access underneath to work on the exhaust... I assume you'd need the cat right off the car to weld it ? Can anyone describe to me whats involved in disconnecting the cat at the front ? Does the flexible coupling joint just unbolt and come apart easily ? Then I just unplug the oxygen sensor and carefully feed the cat out through the bottom without bashing the oxygen sensor ?

The end of the pipe from the middle silencer is a bit burnt away on one side by about 10mm or so, (see pics earlier in the thread) so I'm hoping that we would be able to cut the end off it and weld on the joint that is coming from ebay to replace the burnt bit...

Anyway let me know when you might be able to look at it, it will be nice to meet another FCF regular, after 7 years of posting on the forum and 3 years living on this side of the world the only FCF member I've met face to face thus far is Lexi

[CitroJim]

Pleased to hear a reset of the auto-adaptives has helped Simon

Can anyone describe to me whats involved in disconnecting the cat at the front ? Does the flexible coupling joint just unbolt and come apart easily ? Then I just unplug the oxygen sensor and carefully feed the cat out through the bottom without bashing the oxygen sensor ?

Oh yes, What you need is very thin triple jointed arms that reach to your knees

No, seriously, what you do need is a 10mm ring spanner bent so that the ring end is about 45 degrees to the plane of the spanner. This is to get purchase on the tops of the bolts. To get the nuts off you need a small 1/4" drive ratchet with a 10mm hex socket. Soak well in Plus Gas and pray. It's fiddly and best done two-handed with one working the ratchet from the top of the engine bay and one holding the spanner from below although if you are really ambidextrous you can do both single-handed from above. It's a fiddle and I'd have a spare fitting kit of bolts, cups, springs and nuts on hand just in case you have to get violent with it. If the 10mm nuts round off you can hammer on a good 3/8" socket and hope if they are really tight that they will shear off.

I'd remove the oxygen sensor (good 22mm spanner) before removing the cat as they are a tadette delicate. They can be tight and please do it with the cat cold as they do get hot and stay hot a long time. I still have the scar to prove I once did not take this advice

It's not an easy job I'm afraid.

after 7 years of posting on the forum and 3 years living on this side of the world the only FCF member I've met face to face thus far is Lexi

Then next year you must try to attend a rally or three and meet us all