(Home) Waterless coolant

I have discovered an alternative coolant to the usual mixture of water and antifreeze, that has better heat transfer properties, a much higher boiling point, and no freezing point.

It is a waterless coolant that allows engines to tolerate running hotter, without boiling over, and allows the cooling system to run at very low or no pressure, thus saving radiators, pumps and hoses.

Because there is no water in the system, the engine is free from corrosion and electrolysis, and the engine will run well, no matter how hard they are driven or how hot or cold the environment is. It is perfectly suited for the demands of any hard working engine like the Townace.

Because it is water free, the boiling temperature is in excess of 176ºC, which will eliminate hot spots caused by localised boiling within the engine. It wont freeze either, it remains liquid until -40ºC, when it contracts slightly and turns into a light viscous slurry. It will not freeze solid and expand like water.

The only downside to this coolant is that its not available in the UK, it has to be imported, and it’s also a bit pricey when compared to the cost of conventional antifreeze, but its a lot cheaper than a new head or engine. The minimum quantity for export is 15 Litres and the price is £56 plus £34 carriage making a total of £90.

I am seriously considering getting some imported, and was wondering if any one else would be interested, as it might help reduce the costs a bit?

- (#6861) dave Bright, 22 Jan 03

Ouch! Have you got a name for this coolant? Preferably a chemical formula. How did you come across it?

- (#6862) Ian Dunse, 22 Jan 03

check out http://www.evanscooling.com

- (#6863) Clive, 22 Jan 03

correct Clive, its Evans in the states, and they have some pretty impressive testing to back up their claims. I can use my company to purchase a lorry load of it which should reduce the price a lot, if enough people are interested. I am also in contact with the sales manager to see if there is any scope for becoming their UK distributor.

- (#6864) dave Bright, 22 Jan 03

Coolant sounds great bt looking at the web site it looks as though you have to replace the coolant pump and rad cap, and possibly rad if i read correctly
- (#6865) ron coe, 22 Jan 03

Hi Rob,
this caught me out at first as the web site is a little confusing, but that’s not the case.
There are two products here, NPG and NPG+

NPG
This is the original fluid with all the benefits explained on the web site. The only downside is, its viscosity. Its thick and gloopy, and standard cooling systems cannot cope with it. That is why replacement radiators, pumps, thermostats and other modifications are required. This has been improved and is now called NPG+

NPG+
This has all the same benefits as the original only better, and the viscosity is more like water. Therefore as it says on the NPG+ page, (black oil can link) “It is easier to use as it does not in most cases require changes to existing cooling system components”

“Most cases” I believe refers to any standard car with the possible exception of race cars, or very high performance cars.
The only change you may want to consider is a change in radiator cap, so that the cooling system is under reduced, or zero pressure. This protects the radiators, Hoses and water pump.

Hope that helps... Oh hang on, is that what HTH means?

- (#6866) dave Bright, 22 Jan 03

keepus informed if the coolant becomes available in the uk

- (#6921) ron coe, 24 Jan 03

Incredibly good! Just a minor question out there
Does anyone know of any (small or big) car manufacturer, having adopted this product on their vehicles, right from production? Apparently, it's been around for a while, and being a coolant for "life of vehicle" (read the FAQ), it would just make sense, or not?

Manecas
- (#6922) Manecas, 24 Jan 03

This sounds good! Is anyone trying it?

- (#7115) NiK C., 6 Feb 03

Hi Nik

Yes I am planning to try this coolant; recent arrival of newborn son has delayed the project slightly, as has oil leak from the head. Oil stain visible from just under the manifold on the passenger side of the engine at the front. My guess is a head gasket on the way out. No crossover of oil or coolant is evident and no overheating yet.
I am going to order 4 gallons next week, and will get my mobile mechanic to do a head gasket change before I fit it.
Will let you know how it goes.
Regards to you all.

- (#7116) dave Bright, 8 Feb 03


Just an update for those of you that are interested.

55 gallon drum of NPG+ due to arrive today, and I am planning to install some to my bus this weekend.

I am going to replace the thermostat with a new one, standard not modified. I am doing this, not because I think there is a specific problem with the old one, but because it makes sense with 100,000 Km on the clock. Given the cost of this coolant, its a small additional price to replace the thermostat now, whilst I am draining and flushing the system. After all, I don’t want to have to risk spilling expensive coolant on the ground for the sake of £7if I have to change it some time in the future.

Because this coolant has a boiling temperature of 190°C at zero pressure, I am planning to modify a new radiator cap so that it is zero pressure. This will extend the life of the hoses, radiator matrices, and water pump. I’m not sure quite how I will do this, I am thinking of removing the springy bit, and the seal. Any suggestions here would be much appreciated.

Its been a long time since I have tinkered with any oily bits, and I must admit, I’m nervous in case it all goes totally pear shaped on me. Still, thanks to this forum, I know that there are people here that are only to happy to help with advice if I need it so, deep breath, here goes.

dave Bright

- (#8071) dave Bright, 16 Apr 03 2:05

... I'm fascinated. Do keep us posted! ...

- (#8072) tony, 17 Apr 03 3:59

NPG+ Waterless coolant
I installed this coolant to a 1990 Townace, 4x4, Automatic, 2-litre turbo Diesel, with twin air conditioning and heating. It has a twin radiator system and two heater matrices.

Cleaning the system.
I drained out the old coolant, and refilled with water and a chemical flush. I ran the engine for 20 minutes, and allowed it to cool off before draining the system again. Then I refilled with water only, ran the engine for 15 minutes and when cooled, drained the system once again. This ensured that the system was clean, and free from the sludge and deposits that had built up over the years.

This was a good opportunity to find out what capacity my cooling system is. Unfortunately, I failed to realise this, and didn’t collect the old coolant. This meant that I also had no idea if there were any major air locks after the initial fill.

Draining the system.
This is the hardest part of the conversion, and it takes a lot of time and effort to remove enough water. I didn’t, and that was a mistake. 4 weeks and 500 Kilometres after installing NPG+, I still have 4% water in the system.

Drain plugs
When I removed the drain plugs, I didn’t like the look of the seals, and sure enough, one started leaking. Not very much, but enough to loose some very expensive coolant over a few days.

The drain plugs on the two radiators do not allow the system to drain down enough. I am led to believe that it drains 90% On a 10 litre system, that leaves 10% or 1 litre of water. 1 litre of water will expand more than 500 times in volume once it has turned to steam. Fortunately it mixes with NPG+ and doesn’t all turn to steam at once, but it is quite violent as it percolates through the expansion tank, and it does tend to overflow it.

If I were to do another Townace, I would investigate using the engine block drain plug, even if it means purchasing a new plug in case of problems. I would also disconnect the heater matrix hoses, and drain them as well. Removing the heater matrices I think is too much work, and may result in damage to them, but removing the two cooling radiators is a good step.

Thermostat
I made the mistake of buying an aftermarket thermostat with a 25mm opening, 8mm lift, rather than a Toyota one with a 30mm opening, 10mm lift. This may not sound like a big difference, but if you calculate the volume by which each thermostat opens, the aftermarket thermostat has a volume, 45% smaller than the Toyota one. Not a good idea to restrict the cooling system by 45%, especially on a Townace. When I removed the aftermarket thermostat, I noticed the engine end of it, had been damaged by the receptor plate in the block. The washer on the very end was too big to pass freely through the centre hole, and had been bent out of shape. This was causing the thermostat to stick when opening or closing, thus giving rise to some really bizarre temperature readings.

Filling with NPG+
I used an old plastic jug to pour the coolant slowly into the filler neck. Once it appeared full, I started the engine and ran it on tick-over whilst gently revving periodically. I topped up as the air locks found their way out, and the level dropped. I didn’t put any in the expansion tank because, the coolant heats up and expands to fill it up anyway.

Once the system was filled, it was obvious that there was quite a lot of water remaining in the coolant. What I hadn’t appreciated is that the twin radiator cooling system, is too efficient with the vehicle stationary. The engine has very little load on it, and produces insufficient heat, to cause a high enough temperature for the water to boil off. I had the engine running for nearly an hour, and still the water content was nowhere near the 3.6% recommended for Diesel engines. I have had to resort to driving round with the air conditioning on, and at times with 4 wheel drive engaged in low ratio. Even with the high boiling point of NPG+, this is quite a scary thing to do, given the perceived fragile nature of the 2CT engine at high temperatures.

Its worth noting here that tap water contains impurities including air. When the water turns to steam, the air is released. What does not escape through the expansion tank, will collect in the filler neck when the engine is stopped. Likewise the steam will escape, however some of it will condense back into water before it can escape.

Although all the water will eventually boil off, I have had to keep a very close eye on the temperature gauge, expansion tank, and filler neck. I started checking this before each journey initially, and now check it every other morning when its stone cold. I aught to be able to leave it longer, but having broken a wire on the expansion tank during an overzealous cleaning session, I am nervous about leaving it any longer.

Zero pressure
I have modified a radiator cap to get zero pressure, however I have returned too a normal cap for now because of the bizarre temperature readings I was getting. I will revisit zero pressure another time, when the water content is right, and the temperature fluctuations are normal. after all zero pressure has some good benefits, like extending the life of radiators, hoses, and cooling pump. It would be a shame if these qualities were not available.

Summary
I should have got a spare drain plug and some O-ring seals before the installation. I should have replaced the thermostat and its O-ring seal with correct Toyota parts for my Townace, and most of all I should have made a bigger effort to remove more of the water.

Even so, the anti-boil qualities of NPG+ is what first grabbed my attention, and I am glad to have installed it to my Townace. If the temperature gauge rises above halfway now, its more of an “interesting observation” rather than a “heart stopping moment of blind panic”

If other people are interested enough to want to install NPG+, and I have a bit spare I can sell them, I would be happy to advise them, and even help to install it if required.

- (#8482) dave Bright, 13 May 03 6:28

Dave,
Does the overall running temp come down?

- (#8664) Clive, 20 May 03 0:45

I’m not entirely sure that we will see an overall reduction in temperature, due to the odd nature of the Townace system. More likely it will smooth out the hot spots in the head.

My temp gauge used to sit at dead centre. Now though, it still sits at dead centre most of the time, but rises less that half a point on the scale at its hottest, and drops a whole point at its coolest. I am assuming that this is a sign that the water element is slowly boiling off, even under a pressurised cap. The high point reflects the point at which the coolant is hot enough to produce steam, and as the steam is produced, it reduces the temperature of the remaining coolant. ( some law of Physics applies here) Hence the fluctuations on the gauge.

I checked the water content in the top of the filler neck after the run to Warren park and back, and it still shows about 5% water in the system. I suspect I still have 5% water because the NPG+ is so good at transferring heat, it cools some of the steam, which condenses it back to water before it can escape the system. I have refitted the zero pressure cap to expedite this boil off, and will keep you posted.

Dave Bright

- (#8665) dave Bright, 20 May 03 1:21