Replacing coolant

[Yeobh]

This write up is very informative - from " EUTECH INSTRUMENTS" http://www.eutechinst.com/techtips/tech-tips10.htm

 

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Importance of the pH Value in Engine's Coolant

 

All types of internal combustion engines requires the use of antifreeze, anti-boil or simply a coolant to remove heat from the combustion area.

 

Whether it is called antifreeze in the colder parts of the world or anti-boil in the tropical regions, the coolant's function is to lower the freezing point for winter operation or raise the boiling point in warm climate.

 

The most popular choice of coolant worldwide has always been a mixture of ethylene glycol and water, with the ethylene glycol containing selected and specific inhibitors. While coolant is needed to remove heat in all internal combustion engines regardless of the type of fuel used, a regular control of the coolant solution is required to prevent the engine from severe damage.

 

Frequent engine repair and failure can be traced to improper or non existent engine cooling water treatment. Rust, scale, mineral deposit and deterioration of seals are the result of improper or no treatment in the cooling system.

 

From the time the coolant is introduced into any type of engine it starts a gradual degradation process into corrosive acids. This degradation is a function of time, temperature and the types of metals used in the engine and components construction. Once the coolant turns acidic all engine metals start to dissolve. The results are leaking water pumps, heater cores and radiators.

 

With the increasing number of aluminum engines and components the corrosive process is accelerated since the coolant degrades much faster in contact with aluminum than in typical cast iron engines. During the preventive maintenance of any engine, in addition to the freezing point, the pH value of the cooling system should be checked.

 

Most automotive manufacturers provide in the vehicle manual information about the suggested mileage or time to change the coolant. However it is important, because of the different climate and operative conditions, to measure the pH of the coolant every time the vehicle is at a scheduled service.

 

Extensive testing has shown that a coolant pH below 8.3 pH is not acceptable for use in engines due to its corrosive nature. The correct pH value should be maintained between 9.5 - 10.0 pH. Below 9.0 pH it is advisable to flush the cooling system and refill with a new coolant solution.

 

WARNING: Take proper precautions when removing radiator cap and DO NOT remove when the engine is hot. Accurate pH measurement is achieved when the coolant temperature is below 50 oC.

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[Keen]

I got a bottle of open coolant, how long can it last in the bottle?

[5936]

Test if coolant is acidic or alkaline..

Good coolant should be alkaline.

But one of my coolant has degraded toward near neutral.

[5936]

Yep. I read this article.

[Yuan]

This write up is very informative - from " EUTECH INSTRUMENTS" http://www.eutechinst.com/techtips/tech-tips10.htm

 

---------------------------------------------------------------------------------------------

Importance of the pH Value in Engine's Coolant

 

All types of internal combustion engines requires the use of antifreeze, anti-boil or simply a coolant to remove heat from the combustion area.

 

Whether it is called antifreeze in the colder parts of the world or anti-boil in the tropical regions, the coolant's function is to lower the freezing point for winter operation or raise the boiling point in warm climate.

 

The most popular choice of coolant worldwide has always been a mixture of ethylene glycol and water, with the ethylene glycol containing selected and specific inhibitors. While coolant is needed to remove heat in all internal combustion engines regardless of the type of fuel used, a regular control of the coolant solution is required to prevent the engine from severe damage.

 

Frequent engine repair and failure can be traced to improper or non existent engine cooling water treatment. Rust, scale, mineral deposit and deterioration of seals are the result of improper or no treatment in the cooling system.

 

From the time the coolant is introduced into any type of engine it starts a gradual degradation process into corrosive acids. This degradation is a function of time, temperature and the types of metals used in the engine and components construction. Once the coolant turns acidic all engine metals start to dissolve. The results are leaking water pumps, heater cores and radiators.

 

With the increasing number of aluminum engines and components the corrosive process is accelerated since the coolant degrades much faster in contact with aluminum than in typical cast iron engines. During the preventive maintenance of any engine, in addition to the freezing point, the pH value of the cooling system should be checked.

 

Most automotive manufacturers provide in the vehicle manual information about the suggested mileage or time to change the coolant. However it is important, because of the different climate and operative conditions, to measure the pH of the coolant every time the vehicle is at a scheduled service.

 

Extensive testing has shown that a coolant pH below 8.3 pH is not acceptable for use in engines due to its corrosive nature. The correct pH value should be maintained between 9.5 - 10.0 pH. Below 9.0 pH it is advisable to flush the cooling system and refill with a new coolant solution.

 

WARNING: Take proper precautions when removing radiator cap and DO NOT remove when the engine is hot. Accurate pH measurement is achieved when the coolant temperature is below 50 oC.

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Thanks for sharing. This is informative.

[SimplyTWL]

Just to share, recently just replaced my coolant back to toyota super long life coolant (red) color.

Can last up to 160,000km. So if you are driving a toyota, you can just draw up some coolant and check the coolant color.

If it is still red and clear, no issues with it. Dont have to feel itchy like me go do coolant/raidiator flush.

 

I did a coolant flush at Autobacs in Jan this year, they flushed out my toyota (Red) coolant and replaced with some green coolant.

Instantly noticed that aircon like abit not as cold as before.

Went to do some repairs at another workshop and told them abt my experience, they then drew out some coolant from my coolant tank and noticed that the green coolant somewhat is turning milky.. They advised me that its abt time to change coolant, so recently got a new bottle of toyota super long life coolant and replaced it.

 

Now don't know is pyschological or really aircon is turning cooler. My water temperature reading on my scangauge is also indeed lower..

So advice is, best is to use back the coolant meant for your car make.

[5936]

currently, the world largest EG plant is at.....

 

 

 

 

JURONG ISLAND

[Hamburger]

where to buy those limus like test paper, can those use in aquarium be suitable??

[Kb27]

don't mind me asking, what does ph got to do with coolent? i only know my gold fish ph level

New coolant or EG started out as alkaline, around 10~11 ph.

Contaminants etc...start to neutralize the coolant, eventually making it acidic.

That's when it start to chew up your radiator and metal parts from inside.

[Kwanheng]

where to buy those limus like test paper, can those use in aquarium be suitable??

Should be fine,

[Ag123]

the big deal about antifreeze is not about 'cooling' in our hot tropical weather.

n fact i prefer to put more water (than coolant/antifreeze) as this article show that more antifreeze means a lower specific heat capacity and the water pump need to work harder just to cool things down (more antifreeze doesn't help in our tropical climate)

http://www.engineeringtoolbox.com/ethylene-glycol-d_146.html

 

it is all about *corrosion*

 

found some good articles on antifreeze

http://www.sancarlosradiator.com/antifreeze_coolant.htm

http://www.machinerylubrication.com/Read/8...nt-fundamentals

 

in summary:

silicates protects aluminum/steel well but can choke cooling system if unmaintained, hence needs coolant flush / change perodically (2 years). OAT types has no silicates, last longer, but takes longer to form protection, does not protects as well, and can have other problems (http://en.wikipedia.org/wiki/Antifreeze#Organic_acid_technology)

 

looks like no easy answers to the million $ corrosion question, it is a compromise of sorts

many vendors don't even state that key ingredient in their coolants on the labels (e.g. if they are silicate / phosphorus / OAT based) just selling their purported anti-corrosion benefits and leave too much of a black box

 

if it is silicate based, make sure coolant remains alkaline (i.e. ph >7), once solution become acidic a chemical reaction would start to polymerize the silicate to make silica gel and all that hard silica scales, imagine the cooling system get choked with silica gel and hard silica

http://en.wikipedia.org/wiki/Sodium_silicate. trouble is silicates protect aluminium and steel using that thin inert layer deposited on the metal surface, thereby preventing corrosion (this is documented to be very effective compared to OAT types which does not protect as fast)

 

note the ph thing is not universal for all antifreeze, e.g. OAT antifreeze may work at different ph levels (e.g. closer to neutral (e.g. 7-8), instead of more extreme alkaline > 9)

Edited June 11, 2011 by Ag123

[Hmsg]

Sorry newbie question。

 

Got a engine coolant v low warning.

 

Which cap to open to top up in photo attached?

 

Can i use normal tap water?

[Fcw75]

Should be the one on the left of the engine when standing in front.

[Yeobh]

Sorry newbie question。

 

Got a engine coolant v low warning.

 

Which cap to open to top up in photo attached?

 

Can i use normal tap water?

 

This may be of help to you

http://www.1addicts.com/forums/showthread.php?t=401672

[Hmsg]

Should be the one on the left of the engine when standing in front.

Thanks!