XM 2.5 Starting

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rg
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XM 2.5 Starting

Post by rg »

Folks,
Well, I did the glow plugs this afternoon, and it wasn't too bad. Just a case of (carefully) pushing cables and stuff out of the way and removing the "cable troughing" from the top of the engine. And releasing the header tank. It looks far more frightening than it actually is. It reminded me of the birth of my first daughter by caesarean section, having to push all the vitals and gubbins out of the way without damaging stuff.
Thanks to all who gave advice (on the plugs).
However, maybe I was spoilt by the instant starting of the XUD on my Pug 405, but starting from dead cold still seems a bit spluttery and smokey.
Are these "fly by wire" diesels less "instant" than the good old "direct to the pump" type?
Re-starting immediatly after the initial start is pretty instant now. But I am still a bit concerned about the start from dead cold.
Plugs are Beru, the same as the originals, by the way.
rg
rg
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Post by rg »

Update - Paul Johnson at XM Centre (more like "C5 Centre" these days)suggests (no - insists) that it is a leak in fuel preheater allowing air into the fuel lines. The disconnects them as a matter of routine. Has anyone done this?
rg
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noz
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Post by noz »

Hi Rob
When I bought my 2.5 the fuel heater had already been bypassed. I did some research and found out that it was prone to leaks and it was normal practice to bypass it in this country. You'd obviously struggle in the scandinavian countries.
When I had my engine stripped down I saw the reason why ! (you can't see the pre-heater for love or money without taking off the large black plastic structure covering the cam pulley on the battery side of the car) The pre-heater is bolted to the side of the cylinderhead and there's an aperture at that point. This allows the water circulating through the head to touch the side of the preheater. The fuel flowing inside picks up the conducted heat and the fuel temperature rises as fast as the water circuit surrounding the head. However, the pre-heater is made using a die-cast method and there's something seriously wrong with their manufacturing process. The block is porous due to the metal being in very large grains. To look at it you'd think it was made from polystyrene. Needless to say I never reconnected mine when I rebuilt the engine.
Other people I have spoken to confirm that bypassing it is normal practice in this country.
cheers
noz
rg
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Post by rg »

Cheers, Noz,
I have a selectable pre-heater on my Monterey, and I have never used in over four years and minus-five temperatures.
Just to make life a bit easier, what does it appear to be bypassed with? Two bits of steel "inner" piping, 4 jubilee clips, and a length of hose? Motor factor job?
And so does this mean that the block is extremely porous at that point?
Cheers
rg
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noz
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Post by noz »

yes sorry Rob,
I should have made it clear. The appearance of polystyrene is exactly that. It looks like little spheres of metal have been compressed but not very well leaving all the little interstitial gaps between the spheres. The result is a very porous block. It's so bad, I'm surprised they were even allowed out of the factory. Someone must have spotted that the manufacturing process had gone spectacularly wrong.
Then again, if there's a few hundred cars waiting at the end of the production line with no pre-heaters they'd have put anything on just to get them out the door.
btw, what do you mean by Monterey? The post '95 2.5's were called vsx or exclusive. Is yours pre-95?
cheers
noz
aha ! I assumed XM, is yours a Xantia?
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Post by rg »

Noz,
The Vauxhall Monterey is the second vehicle - a rebadged Isuzu Trooper. It has an electrical preheater.
rg
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