My Citroen XM 3.0 PR-Vestige

[xmexclusive]

I gave Dean a copy of the document that lists the change to the engine.
It was the 1994 Model Year presentation so the change was mid 1993.

John

[MTXM]

That's a nice low milage... Plenty of life left in that.

The 110Kish engine that I rebuilt also had no perceptible wear around the cylinders etc. Russ and I think they are pretty robust!

It was the 1994 Model Year presentation so the change was mid 1993.

That is interesting John, so could Dean's engine then be the early type, since the appearance is certainly very similar to mine?
With regards,
Matthew T.

[xmexclusive]

It is thought that the engine Dean collected came from a Mk2 V6.
It may even be the one that I recovered and sent up to Paul a few years ago.

John

[MTXM]

I am sure you are probably correct on both counts there John and did the changes then come with S2? Regards, Matthew T.

[russ92xmsed]

That's a nice low milage... Plenty of life left in that.

The 110Kish engine that I rebuilt also had no perceptible wear around the cylinders etc. Russ and I think they are pretty robust!

It was the 1994 Model Year presentation so the change was mid 1993.

That is interesting John, so could Dean's engine then be the early type, since the appearance is certainly very similar to mine?
With regards,
Matthew T.

Good news. More reason to own one then.....
PSA stuff does seem to be strong. But then the PRV was co designed by Volvo, so it had to be.

[xmexclusive]

Hi Matthew

No the V6 engine changes came at the start of the 94 model year so 12 months before the Mk 2 launch.
It was described as the "TORQUE ENGINE V6"
The cubic capacity was reduced to 2963 cc (instead of 2975 cc).
The reduction was obtained by:
Decreased travel to 72.3 mm (instead of 73 mm).
Diameter of combustion chamber increased to 93 mm (instead of 92 mm).
The compression ratio adjusted by altering the piston machining.
These madifications entailed the evolution of the following components:
Injection ECU's.
Engine harness.
Injectors.
Citroen XM V6 only: different camshaft setting.
New settings for the autobox fitted to the XM V6 couple.
Suspension mods:
ECU, front regulator spheres.
Front suspension rear articulation.
Rear subframe flexible mounings.

Service interval changed to oil and filter every 9000 miles (previously oil 6000 & filter 12000 miles).

It seems that the V6 engine changed in some way most of the years of Mk 1 production.
So swapping engine parts needs a great deal of care and research.
As you point out most of the bits look very similar.
That does not prove they can be successfully interchanged.

John

[russ92xmsed]

Bit of a can of worms then really. That's quite a change to many parts of the car. I'm surprised.

[Dean]

Indeed, im slowly finding out that so much changed and changed often but can look the same, who would notice a liner thats 1mm larger, a crank that reduces stroke by .75mm, its all a bit silly, i like this one for its later wiring loom but also the later 4 HP18 autobox which was modified for 94 with stronger and smoother operating bits a peices on the insides.

D

[MTXM]

Yes I certainly agree with you on the very subtle changes of bore and stoke Dean and I was thinking the same! At the recent Chevrons I coincidentally spoke to Malcolm Savoy who said the gear ratios on the later HP18 were not so good, but I cant remember exactly why! Regards, Matthew T.

[Dean]

The Ratio's never changed Matthew, so far as i know there were changes in the clutch actuators to improve life and 'driveability' the same goals were in mind in tweeks made to the torque converter, valve block and governor.

In answer to your head gasket question;
photo(52) by Deanxm, on Flickr
photo(51) by Deanxm, on Flickr

D