Coolant Testing with a Multimeter (is this real? I did not know this)

[MoPar~Man]

Coolant Testing with a Multimeter

Perform a quick diagnostic test for corrosion in your water pump, radiator or heater core with a digital multimeter.

www.familyhandyman.com

I did not think that the galvanic voltage of the coolant was necessarily an indicator of anything, but I guess it is? Do any cars (modern or not) have such an easy-to-rig sensor for this?

See also:

The Invisible Enemy - Auto Service World

Summer is here and people are traveling to vacation destinations. With the hotter temperatures, trailer towing and air conditioning use, the vehicle’s cooling system becomes taxed. This could ultimately lead to overheating or a cooling...

www.autoserviceworld.com

Would this apply to the modern HOAT coolants as well as the yellow prestone coolant?

 

[70bigblockdodge]

Interesting.
Best advice in all of that is change it at correct intervals or time. Antifreeze is cheap compared to the labor on some of these hidden components.

 

[Darter6]

Yep, Electrolysis. Even in plain water too.

 

[Justin Plant]

The dreaded Dexcool was originally designed to combat this. ( so I've been told ) The problem is "virtually no one" services their cars the way they should. I learned when I was a teen, to always flush your coolant after a system failure. Water pump, t-stat and so on.... Super heating anti freeze changes its properties as well. Next thing you know, 6 mos. a year down the road there goes the head gasket or intake or whatever. I worked for Advance for 12 years. It never failed to baffle me how many folks didn't know where their hood release was.....

 

[CBODY67]

The "magic" of Dexcool was, according to a Buick service rep which came to tell our service people about it, was that it was silicate-free, so water pump seals would last longer, PLUS in the first 300 miles of the new engine's life, the chemicals in Dexcool would coat the entire engine's coolant passages to prevent it from rusting. Which basically meant "no retrofits" to existing engines. That last part seems to be the most significant item, as we still replaced OEM water pumps by 90K on 1990s pickup V-8s. Yet when vehicles came in with other issues later on, "rusty coolant" was not one of them.

The service rep also mentioned that should the Dexcool mixture get contaminated with other colors of coolant, in order to maintain all of the Dexcool properties, a flush and new Dexcool should be done as quickly as possible.

Later, the Valvoline GO-2 was used by Ford and Chrysler had something similar.

IF for some reason, like a radiator cap which bled-off pressure too soon, the system was continually run "low", which also meant the coolant recovery jug was empty, "pink sand granules" would appear in the filler neck, necessitating a system flush, new radiator cap, and new Dexcool.

These things I know from talking to the service rep and being in GM Parts for decades . . . as that supported my C-body "habit" nicely.

Enjoy!
CBODY67

 

[Mike66Chryslers]

The "magic" of Dexcool was, according to a Buick service rep which came to tell our service people about it, was that it was silicate-free, so water pump seals would last longer, PLUS in the first 300 miles of the new engine's life, the chemicals in Dexcool would coat the entire engine's coolant passages to prevent it from rusting. Which basically meant "no retrofits" to existing engines. That last part seems to be the most significant item, as we still replaced OEM water pumps by 90K on 1990s pickup V-8s. Yet when vehicles came in with other issues later on, "rusty coolant" was not one of them.

The service rep also mentioned that should the Dexcool mixture get contaminated with other colors of coolant, in order to maintain all of the Dexcool properties, a flush and new Dexcool should be done as quickly as possible.

Later, the Valvoline GO-2 was used by Ford and Chrysler had something similar.

IF for some reason, like a radiator cap which bled-off pressure too soon, the system was continually run "low", which also meant the coolant recovery jug was empty, "pink sand granules" would appear in the filler neck, necessitating a system flush, new radiator cap, and new Dexcool.

These things I know from talking to the service rep and being in GM Parts for decades . . . as that supported my C-body "habit" nicely.

Enjoy!
CBODY67

The old green stuff is technically called IAT (Inorganic Acid Technology) coolant.
Dexcool is OAT (Organic Acid Technology). It is not compatible with IAT. If it becomes contaminated it should be flushed ASAP, as you said. Also, the additives package will not protect copper, so it can't be retrofitted into our older cars with copper/brass radiators and heater cores.
The stuff used by Chrysler, Ford, and several European and heavy duty engines is HOAT (Hybrid Organic Acid Technology). It has the same long-life qualities as OAT, but is not harmed by contamination with other formulations.*** Also, the additives in GO-5 do protect copper and it doesn't gel if used in cooling systems with air in them, so it can be used in older vehicles. This is exactly the same as Zerex GO-5, except for the colour. GO-5 has a pale straw-yellow colour. It's sometimes difficult to see the level in the overflow bottle.

*** If changing from the green IAT to another type of antifreeze, I recommend against mixing different brands, even ones that claim to be "compatible" or "universal". Prestone All Makes is a HOAT formulation, but that doesn't guarantee that the additives package is compatible with your existing coolant. It may not cause sludge or gelling in the cooling system, but a half-charge of additives from one brand and half from another may not actually provide corrosion protection of the cooling system. Pick a brand when refilling the cooling system and stick to it.

 

[Gerald Morris]

Stick with the green stuff like Zerex or NAPA's shop brand, which also is made by Valvoline. These old machines were made for ethylene glycol soup coolant, and the producers all now claim to be low silicate. I flush my rides Fall and Spring, changing the mixture for the weather, and this certainly helps keep the old stuff working. If I were dropping a modern engine into a C body, I would consider modern antifreeze and coolant solutions, but since I run 60 yr old iron and copper, I figure 60 yr old IA solutions best suit it.