[jango]

Originally Posted by binoyjude

Any idea whats the difference in the blue and green coolants?Can anyone tell me which one is best??

There is absolutely no difference between coolants of different colors ( Apart from the color ). They all do the same job. Its just the dyes used by manufacturers that gives coolants various colors.

Originally Posted by Thad E Ginathom

You should chose carefully according to which suits the colour of your car

Thad that's a good one

[greenhorn]

there is a lot of difference between different coloured coolants!

[Gansan]

Just went through this thread and have a doubt. Right from the day I bought my Alto the coolant level was between the max and min levels, constantly. I referred the manual and found if the level was low (which it was not) the reservoir should be topped up with more coolant up to the max mark. Since I did not have any coolant, I mentioned this to the MASS guys who said it will be taken care of during the first service and not to bother.

When the first service was in progress I was watching the mechanic from the lounge and saw him add something to the coolant tank from a plastic can. I presumed this would be the premixed coolant. But when I asked him later after the service, he said it was just plain water, and that is what they will add for such small differences in the coolant level. I think he must have added about 250 ml to bring it up to the max level.

I am worried because he added plain water instead of distilled water. When I checked with the service adviser he too said it is nothing to worry about, and coolant should be flushed and refilled only at the 20K/2 year mark. Guys, will there be a possibility of scaling/corrossion etc from the plain water? Can I just leave it like that or will it be better to drain the coolant and refill with a proper mix? The car has done 1000 KM after the service and the coolant level has been stable ever since. The operating temp is also very normal.

[sgiitk]

Coolant is essentially Ethylene Glycol. If you plot the freezing point vs coolant concentration the lowest temperature is around 60% coolant. As for heat transfer the best is water. There are other additives in the coolant like anti-rust, pump lubes, colour etc. these do nto make a real difference.

@Gansan: In India (unless you live in Leh, I guess) freezing is not an issue. You use coolane for its anti-rust and other properties. Remember in the days of the dinosaurs (FIAT/Amby) we all used water and changed the water pump ever so often. So adding water is perfectly fine. I normally use 1:2 coolant:water and top up with water when required. Also, as long as the level remains constant between Max and Min do not bother. If it keeps dropping then you have a leak, and find and fix it (mostly a loose clamp) pronto. In the two years between coolant changes I need to top up at most once!

[DRC]

Very informative thread.
While we are at the coolant subject, we need to understand a bit about how the cooling system is designed.

Coolant is of course an anti-freeze agent with some other chemicals to take care of rusting and lubrication of pump.

regarding the boiling point, I am not sure if it actually rises the boiling point of water, while it is necessary to have higher boiling point to have effective cooling. Steam can not tranfer heat effectively. One fo the ways it is achieved is by operating the system at a higher pressure. At higher pressure, the boiling point also rises keeping water in liquid state. Usually a might have a pressure rating of about 1.4bar (mentioned on my radiator cap). So it is al the more important not to top up beyond max- mark. Else, water being uncompressible will lead to radiator leakage(or which ever is the weakest point to blow)

[proton]

Originally Posted by Gansan

But when I asked him later after the service, he said it was just plain water, and that is what they will add for such small differences in the coolant level. I think he must have added about 250 ml to bring it up to the max level.

I am worried because he added plain water instead of distilled water.

No problem with topping up with a little amount of normal water. Distilled water usage is advised to reduce scaling. Normal scale buildup is taken care of during 20k km system flush. BTW, some interesting info:

History of Water Mix and Pure Glycol Cooling System Development

Stage I
Introduced as a superior coolant in unpressurised system in place of water evaporative cooling system

Quote
The PV-12 was initially designed to use the new water/steam evaporative cooling system then in vogue, similar to one previously (and unsuccessfully) used with the Rolls-Royce Goshawk. The new engine was first run on 15 October 1933 and first flown in April 1935 powering the Hawker Hart biplane. Later on the old the company-owned Hawker Horsley became testbed aircraft for the second prototype engine. In 1936, Rolls-Royce decided to invest in a more flexible flying testbed and the choice fell on Heinkel He 70, high-performance German courier aircraft which also had an enclosed passenger cabin from which several engineers could monitor the engine in flight. One example of He 70G powered with Kestrel V was purchased by Rolls-Royce and subsequently used in the Merlin tests during 1936-1937.

Never resolved problems with the evaporative system manifested themselves with all clarity during trials. The system was notoriously failing during taxiing, when there was no cooling airflow around the condensers and thus the steam could not be cooled quickly enough. Similar problems occurred during climbs at high power, this time for the surplus of heat produced by the engine which exceeded the maximum capacity of the cooling system.

Fortunately, in mid-1930s Prestone in the United States has perfected the use of ethylene glycol as a new and cooling medium, much more efficient than water. As glycol became available, the PV-12 was changed to the conventional liquid cooling system instead.

The Development of Rolls-Royce Merlin Engine

Stage II
Modified for use as a mix with water in pressurised systems

Quote
Merlin development might have stagnated after 1940, any further increases in power needed a more efficent means of transferring the heat away from the engine. Rolls Royce responded with a mixture of water and Ethelyne Glycol which was put under pressure. This mixture also reduced the fire risk associated with using pure Ethelyne Glycol. This system was first used in the Merlin XII used in the Spitfire Mk II. The rapid introduction of this system was only made possible by everything Rolls Royce had learnt about pressurised cooling when developing the Goshawk and early Merlin condenser systems.

ROLLS ROYCE MERLIN ENGINE

Stage III

Adopted for ground use on high speed engines that require higher operating temperatures, corrosion and anticavitation protection.

Quote
It is essential to use the permanent antifreeze agent with corrosion protection that is recommended by the engine manufacturer – even when engines are only used in warm regions without frost or within buildings (e.g. generator drive). Specifications regarding replacement intervals and alternative additives for certain regions must also be observed.

MAHLE | Badly eroded - cavitation at cylinder liners

Gosh! Was that too much information?

[Takumi-san]

Excellent resource. I just had my radiator flushed and my mechanic filled it up with water and coolant - unfortunately not battery water (salt free water) but tap water. Oh well, at least my city does not have hard water problem.

Only wanted to debate a point. someone here mentioned that the coolant / anti freeze always needs to have ethylene glycol. I would like to refute that. I have seen several coolants claiming to be ethylene glycol free and thus more environmental friendly. So what do these options use? These are particularly expensive and I went with the cheaper option unfortunately.

[Raccoon]

Originally Posted by Gansan

Just went through this thread and have a doubt. Right from the day I bought my Alto the coolant level was between the max and min levels, constantly. I referred the manual and found if the level was low (which it was not) the reservoir should be topped up with more coolant up to the max mark. Since I did not have any coolant, I mentioned this to the MASS guys who said it will be taken care of during the first service and not to bother.

When the first service was in progress I was watching the mechanic from the lounge and saw him add something to the coolant tank from a plastic can. I presumed this would be the premixed coolant. But when I asked him later after the service, he said it was just plain water, and that is what they will add for such small differences in the coolant level. I think he must have added about 250 ml to bring it up to the max level.

I am worried because he added plain water instead of distilled water. When I checked with the service adviser he too said it is nothing to worry about, and coolant should be flushed and refilled only at the 20K/2 year mark. Guys, will there be a possibility of scaling/corrossion etc from the plain water? Can I just leave it like that or will it be better to drain the coolant and refill with a proper mix? The car has done 1000 KM after the service and the coolant level has been stable ever since. The operating temp is also very normal.

When it is clearly mentioned and known that only distilled water is to be used, there should be no doubts about what to use. Whether little or a lot is used is also not the point. Why use it when its not supposed to be used? Also remember, tap water varies in mineral content depending on the location/source. The only reason why you might want to use tap water is in an emergency where distilled water + antifreeze is not available. But this should never happen as coolant levels dont drop suddenly in modern cars... unless you have a leak or something.

The mechanics at my MASS tried that when I asked them to top it up till the max mark. They attempted to add just distilled water (at least they claimed its distilled) to top it up. When I asked them why only dist. water, they said otherwise I'd need to buy a normal sized bottle of antifreeze just for the small top up which costs around Rs. 300 approx. I told them to leave it as it is. The level is between the max and min mark, so will keep and eye on it and worry about it in the next service.

For my Esteem, a 30% antifreeze solution is to be used (Maruti uses Golden Cruiser). I guess it would be the same for the Alto.

[Gansan]

Originally Posted by Raccoon

When it is clearly mentioned and known that only distilled water is to be used, there should be no doubts about what to use. Whether little or a lot is used is also not the point. Why use it when its not supposed to be used? Also remember, tap water varies in mineral content depending on the location/source. The only reason why you might want to use tap water is in an emergency where distilled water + antifreeze is not available. But this should never happen as coolant levels dont drop suddenly in modern cars... unless you have a leak or something.

The mechanics at my MASS tried that when I asked them to top it up till the max mark. They attempted to add just distilled water (at least they claimed its distilled) to top it up. When I asked them why only dist. water, they said otherwise I'd need to buy a normal sized bottle of antifreeze just for the small top up which costs around Rs. 300 approx. I told them to leave it as it is. The level is between the max and min mark, so will keep and eye on it and worry about it in the next service.

For my Esteem, a 30% antifreeze solution is to be used (Maruti uses Golden Cruiser). I guess it would be the same for the Alto.

@Raccoon
Please avoid answering questions with more questions. State clearly whether you think that I can leave it alone or should flush and refill with fresh coolant/water mix. At least the mechanic was honest and said it was normal water and that is what they use for small top-ups. He could have claimed it was distilled water and I would have been none the wiser. For info this MASS is run by Maruti-Suzuki themselves.

The coolant level was not dropping. It was between min and max levels when I took delivery. I always like all my fluid levels to be at max so wanted them to top up during service. Had I known they would use just plain water, I would have simply topped up with distilled water at home. I always keep a couple of litres for the inverter battery.

[Raccoon]

Your question is not easy to answer. In the ideal situation, you should flush it out. But that involves cost of new antifreeze+labour+time. Is it worth it? Maybe. Maybe not. Also depends on the level of hardness of the water they used. Also depends on what the concentration of antifreeze currently in your radiator. If it is already less than the recommended, further dilution could prove harmful to your cooling system. And when is the next flush due? If its due very soon, you might want to differ any additional expense right now.

So only you can decide...

[proton]

Hi Gansan

I can understand your concern, having been the proud owner of a new car myself. It may not have been a Merc, but it was a big ticket item for me considering my middle class lifestyle.

I therefore took adequate care of it. The operative word is adequate. Adequate care is a result of informed decision making.

Service manuals will not chart out the exact procedure for each and every deviation from the norm, but engineers have working knowledge of the systems and can make their own judgement calls.

Consider, most systems are overengineered, having what is called a factor of safety built into them. Also, most systems have backup features to take care of failure of the main mechanism.

In our case, coolants contain a substance that INHIBITS scaling. Thus this takes care of the possibility of someone using a bit of normal water for topping up. And in your case , you don't have an extreme situation of having ALL the water consisting of hard water.

BTW, some more interesting info:

Sodium is a better coolant than water:

Quote
Sodium is a solid at room temperature but liquifies at 98°C. It has a wide working temperature since it does not boil until 892°C. That brackets the range of operating temperatures for the reactor so that it does not need to be pressurized as does a water-steam coolant system. It has a large specific heat so that it is an efficient heat-transfer fluid.

Fast Breeder Reactors

How is it relevant to the discussuon? Well sodium has been used to cool engine valves and pistons since WW I. Some model VW aircooled engines used these valves. and so does this modern power plant:

Quote
The use of sodium-filled exhaust valves provide effective heat dissipation resulting in long valve life. Due to the unique nature of sodium-filled valves, specific disposal guidelines must be followed when handling or replacing M42 exhaust valves.

http://www.motortraders.net/groups/g...roup=1&menu=89

Takumi-san

See this:
http://www.tegger.com/hondafaq/overh...e_Mag_53_g.pdf

[Gansan]

Thanks everyone! I have decided to leave it alone and just watch the coolant level. It has not changed after >1000 KM of driving, especially even after 325 KM of some continuous, spirited driving in the blazing sun on last Sunday. As Proton and others have pointed out, even if the small amount of normal water is likely to cause some scaling, there must be additives in the coolant to inhibit it. Finally, the MASS I went to is run by Maruti-Suzuki and Sumitomo corp, not some roadside set-up. If they say it does not matter, then it should not.

[ritedhawan]

As far as i know, it is the coolant which is an incredible conveyor of heat . As the coolant + water mixture goes around the engine block and head and reaches radiator, in contact with the incoming air the coolant releases the heat it had gathered.Water provides the cooling effect once the coolant has absorbed the heat during its route along the engine block . A car driven with only water in radiator, runs the risk of boiling that water to such an extent that it turns into steam and thus back-flow from reservoir, because without coolant in the water, the water is not only providing cooling effect but also has to do the job of absorbing heat --a job should have been done by coolant, but since coolant in not mixed, in this case-- this in turn heats the water above its boiling point , result : steam coming out. I would partly agree, that the addition of coolant does to an extend increase the boiling point of water.

Also, water being corrosive, the addition of coolant acts as an anti-corrosive. Another benefit of adding coolant with water.

[Raccoon]

Originally Posted by Gansan

Finally, the MASS I went to is run by Maruti-Suzuki and Sumitomo corp, not some roadside set-up. If they say it does not matter, then it should not.

You have amazing confidence in big names. They are capable of saying "it does not matter" for a lot of things. And they are right - It does not matter to them. Actually, it does matter to them in the sense they can sell you more parts and services.... heheh! It may also not matter for those people who dont keep their cars for long or who don't know or care enough. Otherwise, a lot of things they dismiss as don't matter, DO matter! Anyway, yours is not a very significant issue. But I'v even heard them say things like bleeding the old brake fluid out or mixing grades does not matter, or keeping fluids above the MAX level does not matter... yada, yada...

[Thad E Ginathom]

Originally Posted by ritedhawan

As far as i know, it is the coolant which is an incredible conveyor of heat . As the coolant + water mixture goes around the engine block and head and reaches radiator, in contact with the incoming air the coolant releases the heat it had gathered.Water provides the cooling effect once the coolant has absorbed the heat during its route along the engine block.

Water is the coolant.

That's why it is called a Water-cooled engine.

The other stuff is just additive that does things like preserve the system from rust.

You have devised an amazing-sounding system there, but I am fairly sure that it just does not happen like that at all. In terms of cooling, the additive (which you are calling "coolant") does nothing separate to the water. How can it? It is in solution in the water.

Bad product labelling causes misunderstandings!