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Cox motor parts genuine Honda £20 for 5 litre mixed
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If it’s on the service schedule just do it, keeps the engine block free from corrosion etc.
On the contrary. Corrosion requires oxygen. Once the oxygen in the coolant water is used up there will be no further corrosion. Draining the oxygen free water and replacing it with fresh water plus whatever chemicals are added will provide a fresh supply of oxygen.
I have never changed the coolant in our family Focus - it remains pink and continent at 21 years old. Nor in my 41yr old TR7 except last century when the radiator had to be reconditioned after a too large stone from a recent road dressing pierced it, and when I had to replace the water pump. Changing coolant is just another wheeze to provide extra work for garages. They will try to blind you with pseudoscience about 'inhibitors' losing efficacy, or some such nonsense.
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If it’s on the service schedule just do it, keeps the engine block free from corrosion etc.
On the contrary. Corrosion requires oxygen. Once the oxygen in the coolant water is used up there will be no further corrosion. Draining the oxygen free water and replacing it with fresh water plus whatever chemicals are added will provide a fresh supply of oxygen.
I have never changed the coolant in our family Focus - it remains pink and continent at 21 years old. Nor in my 41yr old TR7 except last century when the radiator had to be reconditioned after a too large stone from a recent road dressing pierced it, and when I had to replace the water pump. Changing coolant is just another wheeze to provide extra work for garages. They will try to blind you with pseudoscience about 'inhibitors' losing efficacy, or some such nonsense.
Personally I feel that changing the coolant on schedule is cheap insurance to prevent huge damage not only by corrosion but also by freezing. Once every 10 years is only £90 at the Honda garage, far less if you can DIY, it could be as little as £2 a year if the £20 coolant is the correct stuff.
As for the oxygen in the coolant being used up surely that is total nonsense. If you used up all the oxygen you would be left with hydrogen (a gas) and whatever the other constituents of the coolant mix is. This is not going to happen is it.
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I agree, let them change it, like all the other fluids in a car it wears out.
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I have just bought 5 litre from Cox to change my Jazz coolant. Readymix. Delivered £21. (Black Friday discount)) . Car will be 10 next year.
I will pay myself £50 per hour to do the job so it will have cost £21.
Changed our Yaris at 10 years
Do I want to risk £££s bills for £20 worth of coolant? Difficult decision? Not.
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I agree, let them change it, like all the other fluids in a car it wears out.
My car has never had a full coolant change after 13 years, tho the cambelt etc was replaced at 10 years. Coolant was topped up to replace some loss during that job, and is still clear blue. Makers (Pug) say it is lifetime coolant - I had my doubts, but it seems OK.
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If it’s on the service schedule just do it, keeps the engine block free from corrosion etc.
On the contrary. Corrosion requires oxygen. Once the oxygen in the coolant water is used up there will be no further corrosion. Draining the oxygen free water and replacing it with fresh water plus whatever chemicals are added will provide a fresh supply of oxygen.
.......as for the oxygen in the coolant being used up surely that is total nonsense. If you used up all the oxygen you would be left with hydrogen (a gas) and whatever the other constituents of the coolant mix is. This is not going to happen is it.
Oh dear. A total nonsense rebuttal from someone who has either forgotten or never passed a chemistry 'O'...or even the lesser GCSE.... level exam. I was of course referring to the oxygen gas (O2) dissolved in the water (H2O), not the oxygen atom in the water molecule.
And as for the antifreeze component of the coolant (glycol or glycerin), this does not disappear or degrade over time.
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If it’s on the service schedule just do it, keeps the engine block free from corrosion etc.
On the contrary. Corrosion requires oxygen. Once the oxygen in the coolant water is used up there will be no further corrosion. Draining the oxygen free water and replacing it with fresh water plus whatever chemicals are added will provide a fresh supply of oxygen.
.......as for the oxygen in the coolant being used up surely that is total nonsense. If you used up all the oxygen you would be left with hydrogen (a gas) and whatever the other constituents of the coolant mix is. This is not going to happen is it.
Oh dear. A total nonsense rebuttal from someone who has either forgotten or never passed a chemistry 'O'...or even the lesser GCSE.... level exam. I was of course referring to the oxygen gas (O2) dissolved in the water (H2O), not the oxygen atom in the water molecule.
And as for the antifreeze component of the coolant (glycol or glycerin), this does not disappear or degrade over time.
I suggest you don't rely on an unproven theory based on your "O" level knowledge - try reading up what experts say on the issue Engine Coolant Basics (machinerylubrication.com)
Generally, coolant degradation is accounted for in manufacturers’ “recommended use” intervals. Conventional coolants containing silicates degrade primarily due to rapid inhibitor depletion. This is because silicates lay down protective layers over the system components as part of their protection mechanism.
Therefore, coolant inhibitors must be replenished or changed regularly to ensure the surfaces will remain protected if the silicate layer is disturbed.
In general, coolants degrade over time as the ethylene glycol breaks down into primarily glycolic and formic acids. Degradation occurs more quickly in engines operating at higher temperatures or those that allow more air into cooling systems.
The coolant should be tested on an annual basis if it is intended to operate the system for several years between coolant changes, and particularly where the coolant is used in severe applications. One test ensures the pH is still above 7.0. Some coolant technologies can protect as low as pH 6.5, however, it is typically not good practice to allow a coolant to operate below a pH of 7.0.
Glycol breakdown products are acidic and contribute to a drop in pH. Once a coolant has degraded, due to glycol breakdown and pH drop, engine metals are at risk for corrosion. Coolant degradation can be slowed by using coolants with extended life inhibitors and by ensuring that the equipment is operating correctly and within designated design limits.
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<< coolant inhibitors must be replenished or changed regularly to ensure the surfaces will remain protected if the silicate layer is disturbed. >>
I am no expert in the detailed composition of antifreeze, but I do have quite advanced chemistry qualifications. I base my statements on what I have found under the bonnets of various cars since the 1960s.
My daughter ran a Clio in the 1990s. That car's handbook made no mention of regular coolant changes, with the result that her car's coolant resembled brown windsor soup, which I assumed was the result of reactions inside the iron lump. I presume the coolant would have been bog-standard glycol stuff to start with.
My present Pug 207 diesel came with 'lifetime' blue coolant which has been topped up once or twice, mostly after some was lost during a cambelt change 3 years ago. It remains blue despite circulating in an iron block, so I assume corrosion has been quite effectively prevented. I've no idea whether it is still an effective anti-freeze, but as there is no visible evidence of breakdown it probably is. Maybe I should find out .....
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Our last 3 Fords came with 10 year coolant changes and since we only kept one over 10 years that was the only one to get a change. New coolant (Ford) was a much clearer than that in the car which was a very dark blue but its probable the specs had changed. No sludge but the engine was all alloy.
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If it’s on the service schedule just do it, keeps the engine block free from corrosion etc.
On the contrary. Corrosion requires oxygen. Once the oxygen in the coolant water is used up there will be no further corrosion. Draining the oxygen free water and replacing it with fresh water plus whatever chemicals are added will provide a fresh supply of oxygen.
.......as for the oxygen in the coolant being used up surely that is total nonsense. If you used up all the oxygen you would be left with hydrogen (a gas) and whatever the other constituents of the coolant mix is. This is not going to happen is it.
Oh dear. A total nonsense rebuttal from someone who has either forgotten or never passed a chemistry 'O'...or even the lesser GCSE.... level exam. I was of course referring to the oxygen gas (O2) dissolved in the water (H2O), not the oxygen atom in the water molecule.
And as for the antifreeze component of the coolant (glycol or glycerin), this does not disappear or degrade over time.
In general, coolants degrade over time as the ethylene glycol breaks down into primarily glycolic and formic acids. Degradation occurs more quickly in engines operating at higher temperatures or those that allow more air into cooling systems.
The only way glycol can 'break down' is by aerobic biodegradation. This cannot happen in a modern car's sealed cooling system. And if I was unfortunate enough to have a car with a bag of silicate in the cooling system, the first thing I would do would be to remove it before it burst and clogged things up, as many unfortunate owners have found to their cost.
Of course coolant manufacturers' 'experts' recommend regular changes....'they would, wouldn't they?'
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<< The only way glycol can 'break down' is by aerobic biodegradation. This cannot happen in a modern car's sealed cooling system. >>
I'm not so sure about that assertion, John. After a few years in a well-used car an aqueous solution of glycol with a few other trace contaminants will have been kept at about 100°C for perhaps 1000 hours. Not many molecules will tolerate that 100% I imagine. Hydrolysis gets to most things in the end.
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<< The only way glycol can 'break down' is by aerobic biodegradation. This cannot happen in a modern car's sealed cooling system. >>
I'm not so sure about that assertion, John. After a few years in a well-used car an aqueous solution of glycol with a few other trace contaminants will have been kept at about 100°C for perhaps 1000 hours. Not many molecules will tolerate that 100% I imagine. Hydrolysis gets to most things in the end.
In theory perhaps. Actually, in our 21 year old Focus, presently at over 160,000, assuming 140,000 miles at warmed up temperature and average 30mph, that's nearly 5,000 hours at presumably around 90C. As our son is with us till xmas, I conducted a little experiment this afternoon. I put a sample of the original still pink coolant in the freezer compartment next to a thermometer for four hours. At the end, the thermometer read minus 15C and the coolant was perfectly liquid with no sign of slush forming. Rather proves my point, don't you think?
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<< I put a sample of the original still pink coolant in the freezer compartment next to a thermometer for four hours. At the end, the thermometer read minus 15C and the coolant was perfectly liquid with no sign of slush forming. Rather proves my point, don't you think? >>
I think the persistent colour is meant to indicate that the coolant has not degraded, just as I make the same assumption about my blue coolant. It may also indicate that there are additives which may prevent degradation, all to the good.
But you really need to find at what temp your coolant starts to slush, which is probably beyond the scope of a home freezer. It would be interesting if it can reach the same low temp as when you put it in originally - that would be the complete proof.
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Oh dear. A total nonsense rebuttal from someone who has either forgotten or never passed a chemistry 'O'...or even the lesser GCSE.... level exam.
I did pass O Level Chemisty back in the 70's and all we covered was that fact that water as H2O, no mention of "free oxygen gas disolved in the water".
And as for the antifreeze component of the coolant (glycol or glycerin), this does not disappear or degrade over time.
The manufacturers say it does and I trust their view far more than yours.
See reply from RT which seems to cover it.
Edited by thunderbird on 11/12/2021 at 12:36
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<< ... all we covered was that fact that water as H2O, no mention of "free oxygen gas dissolved in the water". >>
Tap water will always contain dissolved air, which you will recall is about 20% oxygen. If your local tap water is soft enough to be added to coolant, boil it first to de-aerate it, especially in winter when more air is dissolved in colder water.
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<< ... all we covered was that fact that water as H2O, no mention of "free oxygen gas dissolved in the water". >>
Tap water will always contain dissolved air, which you will recall is about 20% oxygen. If your local tap water is soft enough to be added to coolant, boil it first to de-aerate it, especially in winter when more air is dissolved in colder water.
Suppose you mean air bubbles. Surely if you let the water stand for a day or 2 in an open container before using it the bubbles would have risen to the top and gone into the atmosphere.
Should ready mixed coolant be free of this issue.
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<< ... all we covered was that fact that water as H2O, no mention of "free oxygen gas dissolved in the water". >>
Tap water will always contain dissolved air, which you will recall is about 20% oxygen. If your local tap water is soft enough to be added to coolant, boil it first to de-aerate it, especially in winter when more air is dissolved in colder water.
Suppose you mean air bubbles. Surely if you let the water stand for a day or 2 in an open container before using it the bubbles would have risen to the top and gone into the atmosphere.
No, I don't mean bubbles. Mains water at ambient temperature will always contain dissolved air, especially if it has been under some pressure. At this time of year mains water will be quite cold and dissolved air may be visible as cloudiness when first opening a hot tap. Some air might escape if cold water is left to stand, but plenty will remain in solution.
Another way to degas water might be to put it under vacuum. That would prove my point. Has to be said, though, the amount of dissolved oxygen at ambient temp is pretty small - about 10mg per litre ....
Edited by Andrew-T on 11/12/2021 at 15:04
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