LHM in freezing conditions?

[romie]

Hiya, a bit of pre-alpine snowboarding forethought....

Has anyone experienced any problems with LHM fluid in very cold conditions?

Say at around -20 Degrees Celsius?

I'm thinking that the viscosity might just become too thick and potentially cause an issue?

Thanks, romie

[Mandrake]

Haven't heard of any problems with LHM in low temperatures, plenty of Citroen's survive Scandinavian winters. I'd be more worried about making sure the radiator had the right concentration of anti-freeze...

[Peter.N.]

I have been running hydropnumatics for about 30 years, we have had a few cold winters in that time although probably not that cold, but as Simon says they are all over the world so I don't envisage a problem.

Peter

[romie]

Fantastic, good points. Thanks Simon n Peter

[qprdude]

Blimey! You expecting -20 in Oxfordshire?

[romie]

Blimey! You expecting -20 in Oxfordshire?

Someone started reading from the bottom..

Hiya, a bit of pre-alpine snowboarding forethought....

Hahah
;p

[VertVega]

Has anyone experienced any problems with LHM fluid in very cold conditions?
Say at around -20 Degrees Celsius?

I have taken the below pic after the small amount of LHM+ stayed
at -25 ºC over 12 hours. There was no visible change in the consistency of the LHM.
The jar I used was a small (~2 dl) baby food jar. At - 32 ºC there was slight visible
change in the transparency of LHM but still it was "liquid"



Edit: At the same time I had another experiment going on with the engine oil of about 0.4 l
Fully Synthetic 5W 40 (Total) and the results were as seen below:

[romie]

Hi VertVega, nice little experiment you had going there

Interesting, so the LHM held up a lot better than the engine oil?

Am I right in thinking you noticed that the LHM didn't change viscosity much.

But the engine oil did get a lot thicker?



I use this cheapo ASDA stuff, but I change oil and filter (Mann filter, got a box of x 10 ), every 6000miles religiously. (maybe I should just purchase a 25litre drum of good stuff at the same price/litre. Any suggestions greatly appreciated?).



This oil will probably be a lot worse than the Fully Synthetic 5W 40 you've got going there.

I wonder if going to the alps, I should use a different weight oil?
I don't think my 1996 250K Xantia is meant to run on anything other than mineral oil? I wonder if I'd get any negative side effects if I used any sort of synthetic. Too slippery on some of the components :/ ?

It's a dry clutch so that won't get effected.
The syncro rings are in the transmission and so they get their own type of oil..

Hmm interesting, dunno :/ ...

[VertVega]

I have no idea about diesel engine motor oil grade. I have to ask from my colleagues at work who drive diesel cars. I drove several times with my car to warm climate countries (for example Italy) and engine oil was still 5W40.

At -25 LHM didn't change viscosity at all. Even such a small amount of LHM (less than 0.1 l) kept its transparency, viscosity and color.

Here are some arctic experiences and advices:
- Cold start needs good battery.
- I use 5W40 and during winter season sometimes I use 0W40.
- Winter season I use engine under tray and I use a cover in front of the radiator air intake.
- Usually cars are preheated here (either coolant or engine oil is heated).
- Make sure that the coolant can still "survive" at below -20
- Don't forget winter tires
- Shovel and warm clothes are good to have in the trunk during winter season.

Cover in front of the car is to prevent the oil breather hoses from freezing.
If the breather hoses freeze than the engine oil will come out from the weakest place.

[isisalar]

I seem to recall when discussing LHM getting very hot someone pointed out that the LHM is heated up quite a lot by the action of the pump anyway. This is very obvious from the p.a.s. on cold mornings if the LHM is getting a bit tired. Soon loosens up with a bit of lock to lock.
Cheers
Paul

[Stickyfinger]

On my old rally car I had a pre heater form kenlow fitted, I have seen many using a 12volt fan heater via some ducting onto the sump...seems to work well.

(Old 20/40 oils were thick in the summer, like grease in the winter untill warm)

[romie]

right'o, thanks for responses

[Richard_C]

Aeons ago, I think maybe 1976, we had a very cold winter here in the UK and I recall one night when it dropped to -17 in North wales. I was driving a Dyane well after midnight and needed an ice scraper for the inside of the windscreen plus all my outdoor clothes on.

The main problem then was diesel waxing and blocking filters, lots of stranded trucks. I remember diesel additives in the early 80s, but I maybe it's in the mix now because I never hear about waxed diesel these days. I wonder if the standard pump mix is different in different parts of Europe?

I used to worry about such things, but now my preparation for a trip to the Alps is just extra de-icer in the screenwash, chains In the boot and off we go. LHM must be OK otherwise there would be huge piles of bent and rotting Citroens at the bottom of every mountain pass after their brakes froze up and they ran off the road.

Here is the spec for Shell LHM, pour point is -55 C.

http://www.epc.shell.com/Docs/GPCDOC_GTDS_Shell_LHM-S_(en" onclick="window.open(this.href);return false;)_TDS_v1.pdf

[RichardW]

'Old' LHM can be affected by extreme cold - I've had heavy PAS and odd suspension behaviour when it's very cold.

UK diesel changes spec in the winter to have a lower cloud point (ie where it starts to get solids in it), -12 I think. I had trouble starting an HDi at about -15 when it had been stood for a few days - our friends who lived in the Clyde Valley were unable to start their 308 HDi during the same period. I had no problems with my Xantia HDi during the same period, even starting it down to -20 - but then it was used for a good run every day.

[Peter.N.]

Slightly of topic but when I had my first diesel car in the late '50s (Perkins 4/99 in a Cresta), it wouldn't start in the winter because the diesel set. I remember people lighting fires under the sumps of lorries around that time because the couldn't start them - how things have changed.

Peter