At what temperature.....

frenchcarnut · Post by **frenchcarnut** » 07 Dec 2010, 10:20

....will modern diesel (50% veggie oil added) start to freeze?

-11 °C this morning when I had to get up at 5.30 to start de-icing the car. I thought something would've clogg up by now, but it started like a dream with the new Varta battery.

Used to hear loads of stories of lorries breaking down sue to frozen fuel not so long ago.

HDI · Post by **HDI** » 07 Dec 2010, 10:36

Can't say how WVO affects diesel, but normal diesel will start to cloud at around freezing point and will start to cause problems at -9.5 C.
Fuel companies have winterised diesel for this time of year though, so it should never be a problem in the UK. It doesn't get properly cold here, try -40 and below and you know it's cold !

Post by **RichardW** » 07 Dec 2010, 11:11

UK Winter diesel spec is cloud point -10°C filter plug point -15°C. It would take some time at that sort of ambient temperature for all the diesel in the tank to be down to close to that temperature - particularly if the car has been run in the previous 24 hours. My HDi started OK this morning, with the in-car temp showing -14°C - although it coughed a bit at first - suspect it's down a glow plug or two. Took a looooong time to warm up though as I was driving gently (and I think the stat is knackered!)

Citroenmad · Post by **Citroenmad** » 07 Dec 2010, 11:30

I had been wondering about the diesel in cold weather too. Though hopefully we wont see it cold enough to cause problems.

Mine stared very well this morning, its new battery is doing the job.

Post by **Peter.N.** » 07 Dec 2010, 11:37

In my youth I remember seeing lorry drivers lighting fires under the engine in these sort of temperatures to get them started, even my early Perkins engines were very difficult to get going, I used to put a gallon of petrol in the tank, that improved it a lot - don't try it with a common rail engine though.

Peter

evilally · Post by **evilally** » 07 Dec 2010, 12:01

A good idea if you are a veggie/bio user is to leave a sample of what's in your tank in a jam jar outside. If you see the stuff in the jam jar go cloudy, then the stuff in the tank will still be ok, but not far behind. The XUD is a tough old bird though, it will run on veggie approaching the consistency of porridge. Also 5% petrol will make a big difference.

A benefit of fitting a flat plate heat exchanger to the fuel line is that it ensures any globs solid veggie get turned back to liquid, and hot oil is returned to the tank keeping it nice and clean.

addo · Post by **addo** » 07 Dec 2010, 18:05

Is there not any kind of snake (for want of a better word) you can feed into the tank via the filler neck, that warms your fuel overnight?

In cabinetry there are reasonably thin heated rubber blankets made to spec for some glueing and bending operations where even warmth is required. I wonder if something similar can't be adapted to the situation...

spider · Post by **spider** » 07 Dec 2010, 18:35

I removed the 'back of block and I like to take air in' fuel heater on mine.

And made this:

Note, cable ties are only there for the 'look' they do not form any part of holding it together

That's the coolant return pipe so always warm.

Looks untidy but does work reasonably well, the derv does not really appear to get more than lukewarm, I think due to poor heat transfer.

Still better than nothing which was the alternative.

I don't run veg, just pointing out a quick DIY thing really, although I made that in a hurry and it could be improved.

Here is an 'in progress' pic:

For reference, the large 'coolant' pipe is standard central heater / mains water piping and the 'fuel' pipe is the microbore central heating pipe, simply shined them up, lay some solder on top and gently warmed them on the gas hob (when no one was looking)

EDIT... Fixed Huge pic.

frenchcarnut · Post by **frenchcarnut** » 08 Dec 2010, 08:52

Some cracking ideas, thoughts and solutions here.

Meanwhile, back in Brum, it was a balmy -2°C. I only needed 3 layers instead of the recent 5, and I felt like getting out the ice cream.

HDI · Post by **HDI** » 08 Dec 2010, 09:33

Just remembered, I recall reading in the handbook that Citroen actually recommend adding a small percentage of petrol to the diesel in very low temps !

vince · Post by **vince** » 08 Dec 2010, 19:32

frenchcarnut wrote:Some cracking ideas, thoughts and solutions here.

Meanwhile, back in Brum, it was a balmy -2°C. I only needed 3 layers instead of the recent 5, and I felt like getting out the ice cream.

Funny you should say that...i stopped off for a Magnum last night on the way home at the petrol station

Heater is on in the van so its still ice cream weather

Post by **RichardW** » 08 Dec 2010, 21:34

Just been out and started SWMBO Picasso. It's currently -10 and has been down to -15 last night, and the Pic hasn't been out since Sunday. Once I'd got over the problem of not being able to open the doors (got the boot open so put the fan heater in it and managed to get in it eventually) I was able to start it - just! It took a fair bit of cranking with periodic coughing before it would run. OK once started. So it would seem that some time at this sort of temp is enough to prevent starting. A night at -20 and it will be game over I think!

Post by **myglaren** » 08 Dec 2010, 21:53

Just a bit of a nip in the air!

It was -38°C in Poland last Thursday - 50 people have died from hypothermia

A balmy -4° here.

Post by **quintet** » 23 Dec 2010, 22:43

Slightly off topic this i realise but i went out in my car today & was rather miffed to 'hear' my (sony) CD player acting up (thoughts of buying a new stereo or even removing a faulty one didn't fill me with joy!) i ejected the CD to find it covered in a light frost

, i cleaned the frost off & tried again but it soon started skipping & then packed up altogether, i resulted in listening to the radio in order to warm up the head unit which then cured the fault.

In all my years of motoring i've never seen a CD get covered in a light covering of frost whilst still inside the stereo, i wouldn't mind but the car was still in use at 7pm+ the previous evening & has never suffered with any sort of dampness/excessive condensation, i guess I'll just have to turn the stereo up to get more heat into it

XantiaMan · Post by **XantiaMan** » 24 Dec 2010, 08:57

Not diesel of course, but my Activa has started PERFECTLY in minus 10, only a slight slowing of the starter but it fires the moment the engine turns, pretty impressive, and shows good compression and overall health.