Electrical Can a bad starter solenoid cause electrolysis? (On my 5th alum rad in 3yrs)

May 31, 2018
4
2
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Oregon
Hey guys, I have a 93 mustang that eats radiators. Like each one lasts 3-5 months and then just starts pissing. I tried multiple different brands, I'm pretty sure it was electrolysis. On the last rad, I got a sacrificial annode that hangs from the rad cap into the coolant. It seemed to be working for about 6 months. Then I started getting coolant overflowing and coming out my small overflow tank. I think then th coolant got low and the annode was no longer inside the coolant, which allowed the electrolysis to eat my last rad. During this problem the voltage in the coolant was always well above 0.3v. like 0.5v usually.

So I checked the grounds etc, all seems good I did the super duper flush with like 8 gallons of distilled water etc bought premixed coolant and it still read like 0.4v. Recently, the car actually got stolen and recovered a week later. After I got it back the starter solenoid went out( had one last crank for me to drive out the chop shop though haha). I get a new advance Auto solenoid and install it. I top off the radiator with distilled water. I decided to check the voltage, and to my surprise it read 0.18. which is below the 0.3 volts they say is damaging.

Now I did drive it prior to taking the reading, and I started it up for a minute or too and read the voltage again, it still said 0.18 volts.

Can a bad starter solenoid cause electrolysis in a radiator?

And I will be putting a bigger overflow tank(stock one back in)

Thanks for any info. I dream of a day where my radiator lasts more than 4 months!
 
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Mustang5L5

i'm familiar with penetration
Mod Dude
Feb 18, 2001
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Massachusetts
Not likely, but i wouldn't rule it out right now.

My question is where do you have the battery ground connected. What about the ground on the back of the driver's cylinder head?

Is the radiator isolated from the chassis with rubber cushioning on the bottom and the top radiator clamps?
 
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7991LXnSHO

10 Year Member
Sep 1, 2010
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Across where are you measuring voltage in the radiator or coolant? If you have done a super flush and used the right antifreeze, I suspect you have a ground problem where the coolant and radiator are in the circuit. Try cleaning the main and firewall ground wires contacts locations. And at the cost vs the cost of radiators, I’d replace the big engine ground cable.
 
May 31, 2018
4
2
13
22
Oregon
Not likely, but i wouldn't rule it out right now.

My question is where do you have the battery ground connected. What about the ground on the back of the driver's cylinder head?

Is the radiator isolated from the chassis with rubber cushioning on the bottom and the top radiator clamps?
I got the rubber mounts top and bottom with a sve radiator. I did clean the ground connection firewall to cylinder head with sandpaper, and the battery ground cable goes to the engine block. The engine block cable looks a bit green. I tested the voltage in the coolant while it was running and it was under 0.17 volts.

Before it was stolen, and I switched the starter solenoid, it always read 0.5v in the coolant. They stole my sub woofer and amplifier, and my stereo always had a weird issue I presume ground issue cuz if I turned it up too loud it would crackle.

So solenoid and amplifier/sub are the only thing that have changed.

I guess it's fixed though, below 0.3 volts...
 

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May 31, 2018
4
2
13
22
Oregon
Across where are you measuring voltage in the radiator or coolant? If you have done a super flush and used the right antifreeze, I suspect you have a ground problem where the coolant and radiator are in the circuit. Try cleaning the main and firewall ground wires contacts locations. And at the cost vs the cost of radiators, I’d replace the big engine ground cable.
I'm putting the multimeter ground on the battery ground and the positive suspended in the coolant not touching the metal. I do have a new ground cable I think, might try that. But it seems to be gone now, at 0.17 volts. Which from what I have read isn't too high to worry about.
 
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May 31, 2018
4
2
13
22
Oregon
I figured it out I think. The aluminum bracket I made to attach the electic fan to the radiator was contacting the chassis, on the bottom of the rad core support. I had just installed the new rad and voltage was back up to .6 volts in the coolant.... So I moved the fan around and remembered the braket. Lifted it up a bit so it's not metal on metal and Walla 0.2 volts only...

If you having electrolysis issues, make sure your radiator is electrically isolated and not touching the frame! Check good!

So we will see if it lasts more than a few months but I'm thinking 5th times the charm (thank God for warranty lol). I put rubber edging to stop the metal on metal contact.
 
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