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The dealer mentioned a chemical reaction in my cooling system between aluminum and other metals that is eating my heater core (4th one in 6months). The GM man that gave me a ride home after I dropped my car off at the dealer said something about putting zinc strips in the cooling system so the electro/chemical reaction attacks the zinc instead of the metal the heater core is made of. Anybody heard of this before?
 

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White Diamond '03 DHS (with DTS floor shift)
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Sounds fishy to me. If it where true, wouldn't we all be replacing heater cores every month?
 

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2001 DTS, 2005 Mustang GT, 2010 MINI S
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This is from a different site. I did not write this.


"HVAC
Save Yourself The Comebacks: When working on vehicles with heater core failure, I use this tip to ensure that I never have a comeback on heater core replacements. With my DVOM set on the DC scale, I connect the negative lead of the meter to ground and immerse the positive lead into the coolant in the radiator neck. I run the engine at 2,000 rpm and look at the DVOM reading. If it’s more than 0.4 to 0.5 volts, there is excessive voltage being introduced into the cooling system via the coolant and aluminum cooling system parts.
I flush the system, put in a batch of fresh coolant, then retest with my DVOM. Flush-and-fill sometimes clears up the excessive voltage, but to make sure, I run a few grounds from the heater core to the engine, thereby eliminating any possible electrolysis. So run that redundant ground; it will save you many possible comebacks."


Logan Diagnostic
www.airbagcrash.com
www.ledfix.com
www.logandiagnostic.com
www.logandieselusa.com
www.crashdatainfo.com
 

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2001 DTS, 2005 Mustang GT, 2010 MINI S
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I should also mention.....

Some engines use a scraficial piece of metal for this. Alfa Romero engines used a magnisium plug that screwed into the cylinder head. These had to be replaced every so often.

Your home water heater also has a replacable rod for this same issue.


Typically with cars, good coolant and good engine grounds will prevent this.


Logan Diagnostic
www.ledfix.com
www.crashdatainfo.com
 

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2008 SRX-V8, 1991 Eldorado
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The problem you reference is called galvanic reaction. Although an electric charge is present, it is the direct result of dissimilar metals chemically reacting with one another. A discharge link or ground wire will help to reduce the reaction but will not arrest a problem that is in the advanced stage. Sacrificial parts as mentioned are called anodes which when statically placed and are of the correct composition will erode as the reaction takes place acting as a neutral buffer.

A coolant system flush done under controlled conditions (not at the local car wash or Jiffy Lube) will help to reduce the problem at the onset but will not eliminate it. GM recommended coolant supplements are crucial during routine maintenance.
 

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2001 DTS, 2005 Mustang GT, 2010 MINI S
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I remember....years ago...

The Oldsmobile Cutlass...'76...'77 models...had the tendentcy to loose their back bumpers.....go figure!

#1 selling car in the US...and after 5 years...oh well...

At the time, I drove a Pontiac Fiero. I allowed plenty of distance between myself and a 76-77 Olds.

The root cause was the metal reacting with the aluminum.


Logan Diagnostic
www.ledfix.com
www.crashdatainfo.com
www.logandieselusa.com
 

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The world has dealt with galvanic action for ages, I don't know why you are having problems with it.
Did you actually look at the old cores and verify that they were decomposing. I just can't see that happening in such a short time.
 

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EcSTSatic said:
The world has dealt with galvanic action for ages, I don't know why you are having problems with it.
Did you actually look at the old cores and verify that they were decomposing. I just can't see that happening in such a short time.
You would know why if you saw the cores when they were removed. How long do you think it takes for a corrosive to eat through aluminum foil? I have seen chemical reactions eat through .062 stainless steel in less than a day.
 

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White Diamond '03 DHS (with DTS floor shift)
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Yeah but you have to admit, 4 cores in 6 months is a bit excessive, don't you. Even if you ran straight Dex I would think they'd last longer than that. Are you sure you didn't grab a bottle of muriatic acid instead of coolant? Are you absolutely sure the failure is due to electro/chemical reaction?
 
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