[Raccoon]

Distilled water is what you should use! Mix it only as per the instructions.

Also, it might not be a good idea to mix coolants... when topping up, buy the same brand that is in your radiator.

[SirAlec]

It doesn't matter if you top it with a concentrated coolant. But my advice would be to go for a branded one. Like Golden Cruiser etc. are good.

[greenhorn]

I'm at 19,200km now. will hit 20 in a month or so, then i suppose I'll be getting the whole thing changed anyway. Thing is , i topped up a little more than a month ago,
http://www.team-bhp.com/forum/techni...nt-brands.html
and its down below minimum again. ( need to check why that's happening ) , and I'd topped it up from elsewhere before. thats why i figured it would be cheaper to do it myself. I went to a tata only parts dealer , and this is what the guy gave .

[Raccoon]

You have to flush ur radiator after sometime/distance. Generally its 2 years. Check you manual.

There are some coolants in the market which are long drain and some biodegradable. Amsoil seems to have one that lasts 7 years! But you probably wont get Amsoil in India... but there are other makes. You may want to check them out. Do NOT mix them!

[greenhorn]

whatever I've been adding has been the regular light green stuff

[joecherian]

I have a related query ? What happens if I add coolant alone (without mixing water). Is it absolutely necessary that you need to add water ?

[HappyWheels]

Originally Posted by joecherian

I have a related query ? What happens if I add coolant alone (without mixing water). Is it absolutely necessary that you need to add water ?

Joeche, please don't do that!

Coolants are meant to be used diluted. Else the thick, undiluted coolant will not even be able to circulate properly, leave alone cooling.

Answer to the question - Yes, it is absolutely necessary to dilute the coolant.

[Gurkha]

Its about transfer of heat, the coefficient of heat transfer of undiluted coolant is quite poor, in fact, most race cars use pure water for the purpose of better cooling. What the coolant does in regular cars is keep the corrosion away as we don't flush our radiators daily, also it raises the boil over point of the fluid inside our radiator and that prevents the fluid from boiling over when temps get hotter than normal thereby negating the need for frequent top ups.

About water, actually due to the ionization factor, Mercedes Benz engineers recommend regular filtered tap water, actually Reverse Osmosis water is the best as its the most mineral free. Distilled water is not recommended so you are safe here.

[anupmathur]

Originally Posted by Gurkha

also it raises the boil over point of the fluid inside our radiator and that prevents the fluid from boiling over when temps get hotter than normal thereby negating the need for frequent top ups.

Err... that is not quite correct. Anything mixed with water can only lower the boiling point of water. The boiling point is raised by having a pressurized system.

[R2D2]

Originally Posted by anupmathur

Err... that is not quite correct. Anything mixed with water can only lower the boiling point of water. The boiling point is raised by having a pressurized system.

Actually Gurkha is right. Introducing 'impurities', in this case ethylene glycol (coolant), in the system leads to the an increase in the boiling point. That plus the pressurised system increases the boiling point to way above 100 deg C.

Rgds,

[R2D2]

Originally Posted by anupmathur

You can add the concentrate to the 'coolant' bottle. This will get diluted as it gets sucked into the radiator in small doses.

That's not quite right. Mixing concentrate directly in the bottle will upset the dilution ratio of the coolant in the engine.

You need to dilute the concentrate in a 1:1 (50%) or 1:2 (33%) concentrate to water ratio. Look at the label for specific instructions or better still consult your owners manual. Best to use distilled water for dilution. Dont use tap water because it could be borewell water which is 'hard' and will cause deposits in the cooling jacket.

Remember, it is water that is the heat transfer agent, not the concentrate. Never, ever mix coolant brands. Always drain, flush with clean water and refill the cooling system with fresh coolant+water mix.
You will be surprised at the kind of muck that flows out when you flush the system.

Change the coolant every 2 years (I did on my Esteem) but with the current crop of cars the factory fill is good for 100,000-160,000 kms.

Rgds,

[R2D2]

Originally Posted by greenhorn

i bought some no name brand coolant concentrate. (wanted to buy premix, but this is what i ended up buying, and didnt notice until i reached home.
I just wanted to top up the coolant , since it dropped below min levels. will there be any issue if i use tap water ( i gather from the previous posts that there is no issue, but some affirmation would be appreciated )

Greenhorn, please dont use tap water unless you are sure it is not from a borewell/well.

Filtered municipal water will suffice but the best option is distilled water, the kind you use in batteries. Not sure about the place where you live, but in Pune we get bottled distilled water for use in batteries and radiators.

Rgds.

[anupmathur]

Originally Posted by R2D2

That's not quite right. Mixing concentrate directly in the bottle will upset the dilution ratio of the coolant in the engine.

R2D2, there is no rigid ratio in which the 'coolant' has to be mixed with water. And, as Thad has oft pointed out on other threads, it is not really COOLANT. It is Anti Freeze additive that we are adding. The most important function it performs is to lower the freezing point of water. Further, it acts as a corrosion inhibitor.
Adding the concentrate to the reservoir will not result in any complications. Small quantities are sucked into the radiator to make up for any losses and volumetric changes due to temperature. This small quantity will get mixed quite well with the circulating liquid/coolant in the system.

Different brands of Anti Freeze can be mixed without untoward consequences, though such mixing of brands is generally best avoided.

[Gurkha]

Originally Posted by anupmathur

Err... that is not quite correct. Anything mixed with water can only lower the boiling point of water. The boiling point is raised by having a pressurized system.

Please check the label on the anti freeze bottle, higher concentration yields higher boil over point, its actually doing the same, that is raising the pressure due to higher molecular weight of the ethylene glycol as compared to water.

I have a simple densitometer from Prestone to test the boil over point of coolant for this specific purpose.

Apart from the MB directive, there is a huge debate on pros and cons of using distilled water, I would personally take RO over any other source. Ironically distilled water sold in India is just ordinary tap water bottled as distilled so the purity is in question. Be safe and use RO.

[R2D2]

Originally Posted by anupmathur

R2D2, there is no rigid ratio in which the 'coolant' has to be mixed with water. And, as Thad has oft pointed out on other threads, it is not really COOLANT. It is Anti Freeze additive that we are adding. The most important function it performs is to lower the freezing point of water. Further, it acts as a corrosion inhibitor.
Adding the concentrate to the reservoir will not result in any complications. Small quantities are sucked into the radiator to make up for any losses and volumetric changes due to temperature. This small quantity will get mixed quite well with the circulating liquid/coolant in the system.

Different brands of Anti Freeze can be mixed without untoward consequences, though such mixing of brands is generally best avoided.

Not really boss. Always check the label for recommended dilution ratios. The only exception is when it is premixed. Premixed coolants are the safest and most are OEM fill. Coolant is a generic term for ethylene glycol + additives + water.

Also, different brands of coolant have different additives which may not be compatible with each other. It is better to play safe and drain the old before adding the new.

As for mixing concentrate directly into the expansion bottle, you can do it if the amount is small. But if you're topping up the bottle from the "low" mark to the "full" (about 1 litre in some cars), then you will introduce a change however minor. All you need to do is mix the concentrate with water and then add to the bottle. It's really not that difficult nor inconvenient to do so.

Rgds.