Coolant PH level questions.

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5 ml in 15 litres of buffered coolant. Someone can do the chemistry but I’d say no way would that amount of acid ( and it’s probably not much stronger than citric acid) would bring that solution down to 5.5. Bogus pH strip results.
 

Grand cherokee hemi

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Thanks everyone... I'm going to drain out a couple liters of the coolant and refill with the concentrate. I suspect that my initial way of "estimating" left me with a ratio of around 55% water and 45% coolant. The recommendation on the bottle is for a minimum of 50% coolant and can go to 60% coolant if live in very cold. I will then re-test with strips and a hydrometer. This will be quick and easy as the overflow bottle probably holds 4+ liters... I will let you guys know.
 
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test strips for aquarium water should work aswell, and should be easy to get in pet stores or even supermarket isles where they sell fish food etc...

You can also test the distilled water and the concentrate (maybe a sample pre-diluted in a cup) just in case there's something acidic happening there.
 
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Thanks everyone... I'm going to drain out a couple liters of the coolant and refill with the concentrate. I suspect that my initial way of "estimating" left me with a ratio of around 55% water and 45% coolant. The recommendation on the bottle is for a minimum of 50% coolant and can go to 60% coolant if live in very cold. I will then re-test with strips and a hydrometer. This will be quick and easy as the overflow bottle probably holds 4+ liters... I will let you guys know.
That would not materially affect the pH.
 

Grand cherokee hemi

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So completely drained my overflow reservoir (about 1.5L) and what I could get out of the radiator without pulling the pedcock about (.5L) and poured in the prestone concentrate. Then drove (with heat on high) until got to operating temp and ensured thermostat opened. Went to MR LUBE and they were kind enough to test for free. The PH now tests at 7.5 which is better (now neutral) but still a little low. The hydrometer test from the radiator still showed the glycol level a little weak. The hydrometer test from overflow bottle showed overly strong glycol, indicating it hasn't fully mixed into the cooling system. This came as no surprise as I expect it will take a couple days for it to get sucked all around. I now have my vehicle running in my driveway with the heat on high.
On an interesting side note the guy at MR LUBE said that you definitely can control the PH by changing the ratio, adding more water will get a lower PH, adding more coolant will get a higher PH. He mentioned that in his personal experience it makes a big difference where the water comes from. And that water (even distilled) varies greatly and often isbelow the normal water PH of 7. I will go back tomorrow and re-test (after the concentrate has had a chance to mix from the overflow bottle).
 
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Since you are in it for the long term why not order up an electronic ph meter and compare it to the strip so you always have at least two sources of measurement.
Good luck. Once those fluids mix you’ll see a higher pH. ;)
 
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On an interesting side note the guy at MR LUBE said that you definitely can control the PH by changing the ratio, adding more water will get a lower PH, adding more coolant will get a higher PH. He mentioned that in his personal experience it makes a big difference where the water comes from. And that water (even distilled) varies greatly and often isbelow the normal water PH of 7. I will go back tomorrow and re-test (after the concentrate has had a chance to mix from the overflow bottle).
MR LUBE doesn’t know what it really means to measure the pH of water, especially distilled water. Such a measurement is nearly meaningless since you’re trying to measure a very small H+ concentration, and it’s a logarithmic scale. Unless your water is seriously contaminated it’s not an issue and can be ignored. pH and its measurement is often poorly understood and his comments reflect that.
 
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