Checking coolant Ph with a multi meter

SDE · Nov 12, 2022

I suggest looking it up on you tube, but set the meter on 20 DC volts. Put the positive lead to a ground and the negative into the cold coolant. Below .05 is good and anything over .07 indicates the the coolant needs to be replaced.

dr sportster · Nov 12, 2022

Good tip !

Steve@Advance · Nov 12, 2022

Interesting...

I watched a couple of the videos, and one was a before and after with new coolant. It did bring the reading down to an acceptable level.

But I would like to see if there is a difference checking in a plastic tank or in a brass radiator, also the length of the lead probe (exposure surface area), and effect of the coolant temperature.

Think I'll check my truck, I can't remember if I ever changed it, if not it's getting really old.

Janicholson · Nov 12, 2022

Try that experiment with a galvanized nail, an aluminum piece, a copper wire, and a silver spoon dipped into the coolant attached to the lead! Then decide id the lead from the meter is a good bet! Jim

Dennis Minn · Nov 12, 2022

I remain skeptical. If I am wrong, then no biggie. I base my coolant testing on lab analysis.
D.

guido · Nov 12, 2022

SDE,

If I recall correctly, it's .3 volts. that will tell you if a DCA (DRY CHEMICAL ADDITIVE) filter needs to be changed, Class 8 diesel truck had a canister with an element just like an oil filter, and also sacrificial palate. All done to keep electrolysis in check.

I have seen where the coolant was so neglected, that piston liners had hole in it because of lack of maintenance. And you can see the pitting on the liner at both side on the liner from top to bottom,

Guido.

Matt in Oz · Nov 12, 2022

Hi SDE

Sorry sounds like hocus pocus to me. Do what is recommended by the company that produces the correct type of coolant for your engine. Never seen pH measured using a multimeter. Multimeter works on electrical flow which can be sustained by charged (ions) moving in solution. pH referes to the acidity or alkalinity of a solution so concentration of hydrogen and hydroxide ions. The multimeter can't tell the difference as to what ions or causing the electric current.

WalJohn · Nov 12, 2022

What the multimeter tests is the corrosion resistance of the coolant.

jimg.allentown · Nov 12, 2022

Are you talking pH or conductivity? As far as I know, the two are not directly connected. Since 7.0 is neutral, any deviation up or down might have similar readings.
I wouldn't trust this method without scientific proof that it is accurate along with a chart to compare your readings to.

Just for the heck of it, have you considered just getting some litmus test strips? They are readily available, and a whole lot more accurate.

For the record, today's engines are full of dissimilar metals - Iron and Aluminum. Add an electrolyte between them and you just made a battery with the iron and aluminum being the terminals. This starts a chemical reaction that will erode the electrodes (the iron and aluminum) until problems arise. The more conductive the electrolyte, the stronger the battery, and the faster galvanic corrosion will eat away at the metals.

caterpillar guy · Nov 12, 2022

Elaborate on this. I've not heard of it before and have always used the strips for the last 20 years or so. They also need to be for the particular antifreeze you are using. IF the old green or if it is the red stuff.

DoubleO7 · Nov 12, 2022

You can also figure the pH level of liquids with a head of red cabbage.

Fordy20 · Nov 13, 2022

Why not just use coolant test strips? NAPA should have them - just check the expiration date.

Checking coolant Ph with a multi meter

SDE

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dr sportster

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Steve@Advance

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Janicholson

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Dennis Minn

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guido

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Matt in Oz

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WalJohn

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jimg.allentown

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caterpillar guy

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DoubleO7

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Fordy20

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