Citroen XM Forum

I ran my previous 1.9XUD Xantia on 50/50 veg/diesel. Never had a problem with it, in fact the hardest part was finding the cheapest oil.

So far the best I have found was 84p and that was a retailer/wholesaler, so I am sure I could get it cheaper. Factoring in the costs of finding it though...

Gave the car a snow foam (just to wind up Dieselman) and a good wash yesterday in preparation for Vince this weekend.



Needless to say on the frostiest morning since picking it up, this and the veg oil were not good ideas as the inside of the windows was iced (moisture getting in) and the car sputtered into life to die again twice before finally the fuel started flowing. So I might put a bit more diesel in the car.

To be honest i have never had a problem with VEG itself even now at near 100% although im sure 2 of my glowplugs are failing.

Failed glowplugs are the main cause for a poor starting veg powered machine.
Check they are all ok.
The xantia benefits from heating the fuel filter which helps a little but not much when the fuel hits the cold injector pipes. The pressure from the pump alone puts a decent amount of heat into the veg.

I get mine for 79p/l from bookers and if your will to stockpile 1000litres you can get it much cheaper, nearer 50p/l for the non edible stuff.
Also the cheap stuff tends to be Soya Based. This has been found to carbonise on the injector nozzles over time so rapeseed is the preferred one by most veggers now, or if using WVO cutting it with BioBoost or such to help thin it out more. Running the tank right down and running some super diesel with additive in helps clean the crud off the injectors as well, about 10-15litres of the stuff should do it and get the engine nice and hot as well.

My Xantia that my dad is using is running on SVO and engine oil at the moment starts first time as all the plugs are fine on it and lacks a little power but it needs a good italian tune up to clear it out as he tends to pootle very slowly all the time and not push the engine ever!
Cutting with a litre or two of petrol is another thing to do but brings the cetane rating down a good bit so winterised diesel is another option a lot of people use.

I find as the 2.5 is lumpy after being started due to the glowplugs that i run it thru two heat cycles and then let it idle while i get into the car, set my laptop bag down, sort the radio and my seatbelt and then drive off.

Merc guys have the luxury of an 'postheat' upgrade for their glowplugs that gives them another minute or two of heat in the plugs. This helps no end with cold running in colder weather and would be lovely to do on the XM/Xantia and possibly could be as easy as fitting another glowplug relay with a different timer delay..

Hi kingp

2.5's have post heat as well.
Corrosion in the power feed wires is another reason for poor starting.

John

Mine doesn't seem to as I can see the lights get a bit brighter a little while after the glowplug light goes out. Maybe it needs the engine to be running to work.

I should add that if I depress the throttle slightly the car doesn't stall upon starting - this morning I started it while clearing the windows as I was hurrying, so I suspect it has nothing to do with glowplugs, simply slightly thicker oil taking its time. Any warmth in the engine at all (even a minute or so) and no problem.

Is the fast idle control working. On cold start the injection timing should be advanced by the lever on the front of the pump and the idle speed should be increased by the one on the rear.

Will (KingP) Charles DID buy the car off me! Do you think Id do a head gasket etc and NOT put new plugs in??

I know that Paul but even new plugs have been known to fail shortly after entering service