To prevent galvanic corrosion?

Koyo Rad leaking - MX-5 Miata Forum

 

I think its cool how people make up stupid crap like this. It makes me want to ground my windsheild washer tank.

 

I didn't ground mine. Never heard of this before.

 

No sense this makes

 

Hey ******* I ground my radiator, bite your tonque! Course I did it cause I ground my fan to the rad and the rad is a shitty ground (rubber mounted).

 

im pretty sure my radiator is bolted to the frame....

 

yeah, via rubber grommet things...

galvanic corrosion is a possibility, but my koyo ate its own drain plug.

 

on the bottom two mounts to hold it steady yeah. but it has two bracket bolted to the side and completely contacting the frame.

 

Mine too, but stock has rubber isolators at the top as well.

 

fine...then my IC is grounding it, lolz

 

Same here on mine.

 

Betcha the radiator was filled with antifreeze plus tap water instead of antifreeze plus distilled water. The tap water down here will eat through the copper pipes in your house in the first ten to fifteen years. After that they replumb it with pvc.

Dissolved minerals in tap water = electrochemical reaction between dissimilar metals. That is as basic as the two plates stuck in a lemon making electricity. Anybody with a saltwater boat should have a story or two to tell about this phenomenon, too.

 

you tell'em Yoda

 

uhm, wouldn't grounding the radiator accelerate electrolysis?

take a voltmeter, open rad cap and hold the + lead in the coolant. put the - lead to ground. report findings.

 

No, because it is the -difference- in current that causes corrosion.


In most cases, I think it is not a worry, but then again, I don't use water in my cooling systems.

 

I was just about to say the same thing. If two dissimilar metals are isolated from one another except by the electrolyte solution, then no current will circulate between them.

And yeah, pure distilled water, plus glycol, should be a pretty ****-poor electrolyte.

From the site linked to in the M.n posting:Ok, so first off, this presupposes that the heater core or radiator represent a path to ground. In the Miata (and most other modern automobiles) neither one of these are connected to ground in any way.

Skip Cannon correctly refutes this asinine idea by quoting the following:The thing is, with pretty much every modern automobile using an aluminum radiator these days, and a pretty large number of 'em still shipping with iron blocks, how many OEMs do you see attaching ground straps or hanging sacrificial zinc anodes inside the cooling system, or other such insanity?

And no, it isn't a conspiracy to force everyone to buy new radiators.


There's no such thing as a "difference" in current. You can have a difference in voltage potential, and if two members with different potentials are connected via a conductive path (such as a ground strap), then you will have current flow.

Think about a simple battery. You have two plates of different material, bathed in electrolyte. Between the two plates there is a difference in voltage potential, but no current flows. It's not until you attach a load between the two plates that you get a flow of current.

 

That makes sense.


Then let me ask you this; why do you think Vanagons were so likely to corrode inbetween the cylinders and the heads (they are both aluminum)? A sacrificial anode did away with this problem. In that case, the engine is well-grounded, but those engines were expected to fail about every 80K miles, due to corrosion.

 

I'm going to say... because it's a volkswagen. And they probably used a coolant solution loaded with phosphates.

 

That would explain what it is not fun to fix, not why it fails.

 

They died from shame.

Seriously though, I'm not intimately familiar with the wasserboxers, as I only ever owned Beetles.

Were the cylinders in fact the same material as the heads? The engine case itself was made from a high magnesium alloy, and I always assumed that the jugs were as well.

Of course, they've got steel liners in them, not sure if that's part of the equation. (Were the liners wet? I've never seen one removed.)

If I recall, the wassers did use head gaskets. Possible contributor?

Too many variables, and my knowledge of that particular engine is pretty limited. On the other hand, consider that those long studs, going all the way from the head, through the jugs and into the case, is electrically similar to a ground strap.