Citroen XM Forum

Would be nice to think that Mark. Lets hope so!


The way you put it......owning an SM sounds like a doddle!!
I know it isn't!!!

Yep, thinking about it there are a few more good things too.....

The rear arm bearings are DS and don't wear out like on the XM and CX: the front under tray is held on by half a dozen bolts and comes off easily to reveal everything; the instrumental panel comes out after a few crosshead screws are removed; the inboard handbrake pads are accessible unlike the DS and the mechanism doesn't seize like on a CX; the radiator is way out front and easy to remove; the front suspension chassis mounts can be welded up in situ unlike a DS which needs the engine taken out; the bonnet is aircraft grade ali unlike the DS; and its only got two doors! So back then Citroen actually thought about maintenance, they made it easier to work on than the DS.

Admittedly the starter is a complete pain to get at, as is the rear height corrector but that's about it. Rush out and buy one now, offer way below the asking price

Cheers

Marc

Wait until you need new discs and a clutch.

The SM specialist in Holland said that the SM engine was a doddle compared to an XM 2.5 or a DS.

It doesn't have great cooling though - Nard puts a triple cored radiator and twin CX fans on his, mine does have a tendency to stall when hot if you take your foot of the accelerator (traffic jams are excruciating). Having met two other owners in the last fortnight, both of whom suffer the same, one suggested it was heat causing the resistance in the HT leads to rise, the spark suffering as a consequence. Given the distributor and points are a weak point - does this sound a reasonable explanation to the mechanically competent? Certainly the cooling fans come on quite late.

You just have to get Citroen eccentric....air con for the engine bay!!

More likely the fuel is boiling due to heat and low pressure or the throttle switch isn't switching onto idle position from running position, alternatively, you have an air leak

Yes I chased that problem for a long time. Hot weather, hit a traffic queue and it would run rough and cut out, then bonnet up to cool down for 20 mins and off we go again. Turned out to be the HT leads. The price of proper SM ones are ridiculous, for no good reason. So I bought a set for an early V8 Range Rover which were cheap and fitted them, problem solved!

If engine is hot and weather is hot and you park up and leave it for 10mins, then fuel boil off does cause issues. Solution is when you crank it over press the throttle to the floor, completely to the floor, and keep it there then crank - starts hot every time that way. Pedal must be on the floor, butterflies wide open.

Other heat issues are old coils, ballast resistors and poor LT wires. If you've got Lumenition ignition fitted then that can play up with one bank cutting out because the sodding electronics in it get too hot - mine used to do that and if I kept it running on 3 cylinders as soon as the car got moving it would cool down and all six cut in then off we go! If you've got points it should run fine in very hot or very cold weather - a lot to be said for having no electronics!

Cheers

Marc

Re the brake discs and clutch......I've changed the discs in situ, which can't be done on a DS as it's an engine out job. And the SM gearbox will come out on its own with the driveshaft flanges attached and the engine staying put, so the clutch can be changed and a CX clutch can be fitted.

Think I'd better keep quiet now, this is an XM forum not an SM one. It's just that there's so much hype about the SM being difficult; it's not, it's easier to work on than a DS, and the engine is superb, it just needs to be oiked out to do the primary chain once every 10 years.

Marc. I like you your a great fellow.. your ds is stunning.. but i haddnt realised you litteraly have one of each big citroen.

Your a lucky man.. prehaps an envy from a few of us.. nice collection. Something id love to have. One of each. But my favorites branch out to othef marques too..

Very nice..

Good stuff Marc, thank you! An early Range Rover V8 set of leads shouldn't be too difficult to source!

A quick question - what do you idle at? Mine is often at 1500 and rarely if ever goes below a 1000rpm. My suspicion is that the D Jetronic has been fiddled with and needs to be reset to factory.

I'm very grateful to everyone here for their indulgence - the SM community is a rather small one and has to get satisfaction somewhat furtively!

Charles M wrote: A quick question - what do you idle at? Mine is often at 1500 and rarely if ever goes below a 1000rpm. My suspicion is that the D Jetronic has been fiddled with and needs to be reset to factory.

I suspect either the fast idle valve is leaking/open or there is an air leak after the throttle body. This is possibly why it stalls.

A full reset should probably sort all your woes and raise mpg significantly.