Xantia diesel engine swap

andmcit · Unread post by **andmcit** » 06 Jul 2007, 20:13

A good pal has offered me his P plated estate which works happily but is
managing to mix the oil and water and although NOT confirmed it's probably
pressurising the water jacket thus confirming the HG is a gonner. I have
suggested he changes the oil/water heat exchanger on the front of the
engine but I'm not sure he bothered doing this; it has been known to cause
such a failure if there IS NO pressurisation on an XM V6 with me in the past!

Thing is, the gearbox has a bit of a snick through the change into 3rd also
suggesting future problems there.

Here's the question!

Would a '93 vintage engine/box sitting handy on the floor here fit straight
in without big hassles!? What concerns me is the compatability of the
diesel pump and I must confess I'm not in the habit of swapping engines
in/out around the place - I'm happy to do clutch jobs but just REALLY
can't be bothered with conversions etc if there's more work involved
than just ploking the same motor back in etc!!

Your thoughts? Anyone done such a thing '93 engine/box into '96 car?

The crock engine is the variety with a strut damper on the diesel pump,
whereas I know the older engine hasn't - incidentally, the older model
engine is 100% with 110k miles and the 'younger' unit has about 160k!!

I'd have a go swapping the engines over this weekend if I knew it
is viable... I have a spare new clutch and both are the 'normal' variety
engagement with separate thrust bearing!!

Andrew

Andrew

Unread post by **CitroJim** » 06 Jul 2007, 20:38

Hi Andrew,

Has the '93 engine still complete with its fully mechanical injection pump?

If it is then it is very simple, just put it in complete and ditch the ECU. All you'll need to do is to arrange an ignition switched supply to the stop solenoid and arrange for the tacho to work in a different way (see later in this post).

I see no reason why the ECU could not be just removed completely, along with the EGR and cold advance electrovalves, neither of which will be needed.

The coded keypad will no longer function.

Swapping pumps between engines is easy enough but you'll need to swap over injectors as No.3 has the needle lift sensor. You may have to swap flywheels as well if the '96 engine has a different one to operate the TDC sensor. Also, you need to ensure the '93 gearbox has the mounting in the right place for the TDC sensor. My '93 TD has taken our caravan for a tug this weekend so unfortunately I can't check to see if it has a hole for a TDC sensor but something nagging in the back of my mind says it has to work the tacho.

That'll be a point, if you use the '93 mechanical injection, you'll have to rearrage the tacho as in the '96 engine it'll be working from the ECU.

You'll not have an EGR valve on the '93 engine but that can be easily lived without.

On the gearbox, the 3rd gear Synchro hub is wearing but it'll go on for eons yet. It'll never let you down.

Hope that heps a bit Andrew

Unread post by **CitroJim** » 06 Jul 2007, 20:52

Sorry Andrew, still pondring this

If you use mechanical injection and ditch the ECU, it'll be worth checking that the glowplug controller is not linked to the ECU for pre-heat timing and post-heating control. You may need a '93 type glowplug controller.

I'd not worry too much about not being able to provide post-heating.

A mechanical pump also has electically controlled cold-start advance on it, controlled by a sensor (green one) on the thremostat housing that via a relay, cuts out the advance when the coolant reaches 60 degrees.

In my experience, neither post-heating or cold advance makes much odds in the UK climate.

Is there aircon involved? If the '93 engine was from a non-aircon car and the '96 is, then the '93 engine will have a tin sump and the '96 an alloy one for the A/C compressor mounts. You may need to swap sumps.

You'll aslo need to swap the Bitron sensor in the thermostat housing.

andmcit · Unread post by **andmcit** » 06 Jul 2007, 21:27

Thanks for the prompt thorough answer Jim!

Gawd, things ARE never simple!!

I believe the car doesn't have a keycode immobiliser - that said, this could
just be because it's been bypassed. I've started the car without a code anyhow.

The business about the flywheel sensor pick up and even the flywheel isn't
unexpected - that's exactly why I was making this enquiry in the first
place!

There are a few different ways of looking at this!!

On the face of things what in fact may be simplest to do is fix the head
issue by changing the head gasket but there's the worry with the baulking
or whatever on the gearbox that may still need an engine out job in the
future anyway.

Then there's the option to use the '93 engine with the '96 pump but there's
a question mark about the similarities/differences etc between gearboxes
as far as the flywheel sensor is concerned and the '96 car DOES HAVE AC

so it's not looking a simple fix is it!?

I guess of course I could just forget about the whole thing! The bodyshell
is near perfect in a nice BA cobalt blue BUT it has no sunroof and doesn't
have ABS I guess due to being the later equivalent of an LX. Many would
say it's not worth the effort sorting it out. There's a nice little historical
aspect to the cars' past which would be a shame to ditch lightly.

The previous owner to my pal lives in Bristol and was one of the senior
engineering ground crew/maintenance bods who looked after Concorde
when it rested at BA's operation there. On it's last visit to Bristol, to mark
Concorde's departure for ever, they all piled into the Xantia proudly
wearing frosted Concorde side window glasses* and symbolically led
the plane out of its service area for take off the last time in an emotional
farewell!!

*The owner fitted the meticulous senior engineer profile to a T and needed
to explain why he had the Concorde plan profile delta wing pattern on the
car side windows. He'd had the car from new and specifically chose the
royal blue metallic as it perfectly suited the area of the plane where it
spent all it's time - he eventually only sold the car as he'd bought a new
Citroen upon his retirement. Seems he was very proud of his accociation
with the plane and retired when it did!!

Great story if true - it was never used as a selling point...

Anyhow, then of course there's the option to get an identical engine as a
swap and ignoring the engine I've got lying around the place waiting to
be used as a spare

Andrew

Unread post by **CitroJim** » 06 Jul 2007, 21:33

Andrew, the car is just too special not to restore with a history like that

And in Colbalt Blue as well

This from a person who was incredibly sad to see Concorde retired

andmcit · Unread post by **andmcit** » 06 Jul 2007, 22:10

Jim, just so I'm clear - the later car/bodyshell doesn't have a solenoid cut
off on the pump - I'm familiar with this arrangement on diesels as I know
the CX DTR lump only 'too' well!! Is this controlled via the ECU instead as
for the life of me, without checking, I'm pretty sure it doesn't have an
ECU/anything on the front offside wing...

So what gets the rev counter working with the older mechanical pump
- this is still attached to the engine prettymuch with all the original cars
wiring loom - is one of these a similar set up on a different sensor?

It's daft, but the car is referred to as the 'Concorde Xantia' by us all!!

Andrew

Unread post by **CitroJim** » 06 Jul 2007, 22:33

Hi Andrew,

the semi-electronic pump has a stop solenoid but it is very effectively hidden under the anti-theft shield and is, I believe, under ECU control via the keypad. So therefore, this would not do for a mechanical pump. All that is required though is an ignition switched supply to operate the solenoid.

There is nothing on the fuel lines themselves remote from the pump to cut the fuel supply.

On a mechanical pump engine I'm reasonably certain the tacho works from a TDC sensor in the same place as the later engine but I don't know if the TDC sensors are the same or if the tacho itself is the same electronically. My guess is that they are because irrespective of how they get them, from ECU or sensor, both are just pulse counters. Ditto the TDC sensors.

Unfortunately, I'm not at home this evening so I'm away from my books and my TD is unavailable although I'll get to see it tomorrow evening. I cannot even log into pr.net to check part numbers because my login credentials are at home

As soon as I'm home in the morning, I'll do some more research Andrew.

andmcit · Unread post by **andmcit** » 06 Jul 2007, 22:39

Thanks Jim - I do appreciate your time already! It doesn't all have to be
done in a hurry at this end - just there's a lot more enthusiasm for doing
such jobs when it's NOT raining!! Guess the car will need a decision
sooner rather than later though!

Andrew

Unread post by **Peter.N.** » 07 Jul 2007, 00:11

I can confirm that the tacho works from the TDC sensor and that it is the same one in both types of engine. I wish you success in doing the conversion, I think it will improve it, the mechanically governed engines are potentially much more reliable. Both my '96 XM's have mechanical pumps on the 2.1 engine, something you dont get with a Xantia!