Waterless Coolant

[Boydie]

Has anyone tried waterless coolant and what if any experiences have they had, on our recent desert trip I noted that in the 40 - 45 deg. C ambient temperatures we were driving in the engine temperature rose by 15 degrees C when the aircon was on, up from 90 to 105 C. now while this didnt cause any overheating problems I would rather the system coped without any temperature change. Waterless coolant seems to have several advantages,it claims a boiling point of 190 deg. C and it does not expand so the cooling system doesnt requires or cause the cooling system to be pressurised, consequently the header tank can be filled to the top with no worries, the down side is the enormous cost, 15 lites at $90 per 5 litres means a total cost of $270 !!

The alternatve is to relocate the A/C condenser to below the roof rack.

[simonr]

From what I've read, adding 'water wetter' to the cooling system makes as much difference to the temperature as the waterless coolant (the Evans stuff anyway). The 'wetter' is just a salt free detergent which breaks down the surface tension and allows better contact between the water & engine components. It also makes the water 'stick' to the pump impeller better which reduces cavitation at high RPM. I believe the temperature reductions attributed to waterless coolant are for the same reason - thus if it's just a temperature reduction you are after, 'wetter' (which only costs a few quid) will work as well.

Where the waterless coolant is good is in systems which suffer from corrosion badly (too badly for the corrosion inhibitor in Antifreeze) and those which are intended to run at above boiling point. Some engines, particularly turbocharged Petrols suffer from localised hot-spots where the water can boil at the hot-spot leading to poorer cooling & even higher temperatures.

Many people like the fact that the cooling system is not pressurised leading to fewer hose failures.

Overall, my feeling is that with the majority of engines, it won't give a benefit worth the cost. For some, it undoubtedly will, but not most.

Si

[Team Idris]

I'd go with moving the aircon condenser to the roof rack. Water-less is very good and in many ways water/glycol is rubbish by comparison. But you still have the problem that the rads fins cannot shift enough heat due to the air stream being hot. Really the best option for reliability would be to do both mods

[Peter M]

You also have add in the factor if switching from normal coolant, you need to flush with a "cleaner " before filling with waterless coolant.

You cant just bung it in !

[FridgeFreezer]

We tried some fancy coolant in the LS, it became a pain because if you needed to pop a hose off to do something, you had to run round & collect the drained coolant (because it's expensive!). In the end we went back to normal water & anti-freeze/coolant - cheap, easy, available everywhere for top-ups. Certainly on an expedition truck I wouldn't run unusual parts or fluids that don't play well with the local stuff.

Air con will always up the temp a bit, you're drawing more power from the engine and throwing a load of heat in front of the rad. 105degC is coincidentally about the temperature the air-con helper fans switch on, so it would suggest your system is working exactly as it should and is not struggling.

[ejparrott]

The boiling point of water is related to its pressure in any case, ~I've not got the calcs to hand but if memory serves me right its about 122C at 9psi anyway

[TJN]

I have used water wetter in my MGB and in the land Rovers when travelling and this has made a significant differnce to the overall temperature, even with a failing water pump in corsica the needle didnt go into the red on a fully loaded 130 climbing 4000 ft.

I use the Redline stuff. http://www.ebay.co.uk/itm/RED-LINE-WATER-WETTER-ENGINE-COOLANT-CONDITIONER-HELPS-CONTROL-OVERHEATING-355ml-/310806484973?_trksid=p2054897.l4276#ht_1467wt_932

[zardos]

Interesting read http://www.norosion.com/evanstest.htm

One of the main points is that the waterless coolant is more viscous so can actually cool less than water due to the decreased flow (I went with much cheaper water wetter for my V8)

[zardos]

Also discussed here before

http://forums.lr4x4.com/index.php?showtopic=79295

[Boydie]

Thanks for all the input, I think I'll go with Team Idris, relocate the A/C condenser to give better airflow through the radiator as well as the intercooler and before I try the waterless coolant I'll try the "water wetter" product to see how that goes first, I really dont like the idea of being locked into a complicated product that isnt readily available, (the local price I was quoted included 15 litres of the "cleanser" to remove all traces of water in the system before the waterless fluid was used) but the idea of a cooling system that isnt under pressure is still very attractive.

[FridgeFreezer]

the idea of a cooling system that isnt under pressure is still very attractive.

Do you mean an unpressurised system or one that struggles less?

TBH if your system is anywhere near marginal with the manufacturer's spec of coolant, you need to fix or uprate the system NOT rely on quick fixes like water wetter. If water wetter or fancy coolant makes the difference, there's not enough margin there.

[Boydie]

quite simply a system that runs at normal operating temperature - in my engines case 90 degrees C with no increase in system pressure. Bear in mind that my VDO guage is measuring the water temperature exiting the thermostat (it replaces the standard gauge sensor) so the internat engine water temp can be as high as 120 C if the thermostat is reading 90.

[zardos]

I will think you find that it is impossible to run a coolant at 90C with no increase in system pressure, even the water less coolant will increase in volume from cold to running temperature and thus will pressurise the system unless you have also changed the system to be open to the atmosphere.

I think what you mean is that you don't want to rely on the pressure increase stopping the coolant from boiling.

If you don't modify the system to be open to atmosphere then your coolant will still be pressurised and have an increased boiling point because of this (so just changing to the waterless coolant will not achieve this goal)

If you do modify the system to be open to atmosphere then you are still relying on pressure to stop the coolant boiling, just that pressure from the atmosphere that is variable and determined by weather and altitude (for example the boiling point on Everest is 71C )

Even then large parts of the system will be pressurised by the act of pumping coolant around it (so will have to be careful on the positioning of any opening to atmosphere if you make that change)

Note that the you can still use normal water based coolant to achieve this goal, the easiest one is just run your coolant at a much lower temperature, say around 65C (would need to increase the radiators cooling capability)
You could also do it with increase coolant flow as well but that would require changes to the pump and radiators

Overall you cannot really beat water for it's thermal properties and I'm sure engine designers have analysied the tradeoff's over the years and picked a pressurised water based coolant as the best compromise.

[Boydie]

The waterless coolant I have been looking at has a boiling point at sea level (14.7psi or 1 atmosphere) of 190 degrees Celcius. At my engines operating range of between 90 - 120 degrees C. the manufacturer claims that there will be zero expansion of the coolant, if that is true, and even accepting your point that there will be negative and posative pressures either side of the water pump the end result, then the system will only be operating at normal ambient atmospheric pressure, so there will be reduced wear on gaskets and hoses furthermore if there is no expansion then the header tank can be filled almost to the top which will mean that the system, (engine, heater and radiator) will be fully flooded. I cannot see any fault with that logic. Most of the big V8 Holden & Ford racing teams use this product for that very reason, and the fact that it doesnt boil.

[zardos]

I find the manufacturers claims of no expansion hard to believe.
A quick google shows that the coolant is glycol based and glycol has over twice the Volumetric Coefficient of Expansion of water so it expands more than twice the amount that water does per 1C of temperature change.

I agree than racing teams might want to use it as they probably want to run hotter than normal and have very high power engines that might suffer more with localised hot spots.
But they will have designed the system to use it to it's best, not put it in a system to use a water/glycol mix.

[Team Idris]

Boydie sounds fair to me. As I understood it, the first thing to do was remove the seal off the rad cap? Then the likelihood of a hose going was reduced massively. This was my biggest like

But, downsides would include the fact that any heat exchanger system works better under pressure, as the fluid is forced onto the conductive surfaces. (probably irrelevant in this case). And that no-pressure might allow/cause a bottom hose to collapse under the pumps suction? (not hard to fix with hard piping).

On fresh engine build with a new rad I think I would go for it. It sorts so many problems in one hit. Something with bluecol in already I'm staying the same.

[Boydie]

i think that just about covers it.