Ok I read this article _Electrolysis Contamination

I was bored today and decided to go over my truck checking fluids, battery condition etc etc.

I broke out my VOM and it is indicated .13 to .15 DC volts when I test the coolant.

The article indicates 01-.09v is acceptable or below.

So I am above that but it also states .3 volts means it has started. So I am in between there.

Do I need to worry? Last spring I drained and back flushed using tap water. I know I know about tap water now. I used green 50/50 premix coolant. I believe it was Prestone. I also used Prestone Flush chemical during the process and followed the directions. I only backflushed with the hose and drained out as much as possible but I realize now that was a no no. Should have filled and drained and so on and on with purified water.

I plan on doing a proper flush with purified water and proper coolant.

I am just curious if the voltage found in my coolant is within normal range or do I need to hurry and do the flush now?

Thank

 

having a differential voltage between two points often means something is not grounded correctly. how about running a ground strap or a 12 gauge copper wire from the radiator or heater core to the truck frame and see if the voltage differential goes away.

 

Also check the ground from the motor to the frame, originally it is just the one in the middle of the neg cable that goes to the frame on its way from the battery to the block. Ford's biggest weak point in the electrical system has always been grounds. Adding grounds will make your computer happier as well. Ford grounds the control components primarily through the ecm.

 

DO NOT ADD A GROUND!!!!!!!!!!!!!!!!!!!!

When adding a ground, you have to make a braid with a diode soldered in the correct direction so stray current can flow back to the battery. (away from the engine).

You do not have electrolysis if you measure less than 0.300 vdc.

However, you fail to mention what engine you have. If you have a 4.6L or 5.4L then switch to motorcraft gold or zerex G-05. Heater core failures ceased when ford switch to this coolant. Do not use prestone all makes and models coolant. It is dexcool clone. It will destroy plastic.

Feel free to use tap water for flushing, and do flush plenty until all fluid comes out crystal clear. Then drain and purge with distilled water with approx 8 gal to replace the tap water. Drain empty. Once you do that add two gal of pure 100% coolant, then top with distilled again if needed.

 

Hi,

ust a little note about using the DVM. It might be worthwhile to try and take the reading with another DVM. If they're both pretty close, chances are everything is good.

I just mention this because DVMs are not always as accurate as they seem to be, and you're talking about some pretty small voltages here.

Probably you're OK, but it's an easy enough thing to check with somebody else's meter.

hj

 

Instead of adding a ground I checked all my grounds. I cleaned a couple of them just from dust and grime. The motor is a 5.4.

When I did the back flush and refill I used the one size fits all 50/50 Prestone. I realize now this was incorrect and will be changing to the appropriate coolant.

After cleaning the grounds and using my other VOM both meters read .13 volts. Only once did I get the higher reading of .15.

The coolant still looks new so this spring I will flush it out and install the correct coolant.

For ****s and giggles I temporarily clamped a ground to my radiator and checked it and the VOM did not change. I also tried to do the heater core, not much metal exposed and the VOM did not change.