Voltage between coolant and ground... bad?

[Jim C]

I just installed a new aluminum radiator ('97 GTS). The instructions said to check for voltage between the coolant and ground (said it was very bad and .15V could, through electrolysis, ruin an aluminum engine). I measured a small current (.15V) that dropped off quickly to almost nothing while testing. I couldn't find anything with a search that seemed to match. Can anyone enlighten me on this? I certainly don't want to "ruin the engine".

Thanks!

 

[FRANK]

Yo man...whose chain are you trying to pull? Is this a joke?

I have run an aluminum radiator in one of my cars and never heard of this high tech jargon you speak of. FIll it up with some Prestone and stop worrying. That motor isn't gonna be hurt by anything you speak of...relax...too many people on here are so anal and sweat stuff unheard of...

 

[GR8_ASP]

So Frank I suppose you would be one to resist using the zinc anode on a boat motor also. Yeh, that electrolysis stuff is just high tech jargon and not to be listened to.

P.S. if you do have a boat make sure you have a stainless steel prop and no zinc anode. That should do the trick if you want to see the aluminum outdrive do a disappearing act.

 

[FRANK]

So Frank I suppose you would be one to resist using the zinc anode on a boat motor also. Yeh, that electrolysis stuff is just high tech jargon and not to be listened to.

P.S. if you do have a boat make sure you have a stainless steel prop and no zinc anode. That should do the trick if you want to see the aluminum outdrive do a disappearing act.

My wife had electrolysis done in her bikini area...pretty impressive to say the least! No more bumps from shaving!

Maybe I should have had her rub some zinc anode down there and would have not costed me a grand to have a bare bikini area? Hmmm....zinc anode may be a new alternative to having permanent hair removal done through electrolysis!

 

[SingleMalt]

Jim - Viper SRT's recommendation was partly in jest, partly serious The main problem here is where should the sacrificial metal go, right? No radiator cap. Hmmm?

Trust the coolant manufacturers; there are additives in the coolant itself that help protect aluminum -- a large majority of engines and radiators nowadays are aluminum. Be sure to use distilled water and correct coolant proportion.

Mike

Borrowed from http://www.yachtsurvey.com:

"When electricity flows from the anode to cathode, it will carry small molecules of the metal with it. This is why zinc, used to protect underwater metal parts, slowly erodes over time. The flow of current is carrying molecules of the metal away to the cathode. And since aluminum drives are basically very large anodes, keeping the drive unit from self-destructing is not easy. Zincs are used because zinc has an even higher electrical potential than aluminum. Thus the zinc is sacrificed to protect the aluminum."

 

[Tom F&L GoR]

Anytime two dissimilar metals are in contact, you have a battery. Aluminum is also a fairly high reactive metal, so the electrolysis corrosion can be significant. Using an antifreeze with anti-corrosion additives is the obvious thing to do, but any unusual voltage paths (perhaps more of a problem with plastic tanks, since the radiator may not be as easily grounded) will use up the protection that much quicker.

Lots of information about it can be found at the library...

 

[Viper Specialty]

JIM-

3 guidelines to follow. If these are OK, you should be fine;

-DO NOT use ANY Brass Fittings in your Aluminum Radiator. Use only Aluminum or Steel fittings. YES, the drain plug from the stock radiator is brass if you happened to carry it over to the new one!

-DO NOT use DexCool coolant. I dont care what anyone says, I have had one of my own radiators ruined by it, and have watched another isolated case unfold in the exact same way. Both were retrofits, and both used dexcool. Both radiaotrs failed within 6 months. Different cars, different people, same coolant, same problem. both bought new rads, used different coolent, and never had the same problem again. no other changes. I highly recomend the Mopar 5-year (RED) coolant.

-Check all engine ground straps.

 

[FRANK]

*DELETED*

 

[Jim C]

Thanks for the input;

I didn't use any brass fittings, filled it up with some good red 50/50 coolant (after flushing 8 times to make sure no green was still coming out). The new coolant says "dexcool compatible", I assume that isn't the same as being dexcool (?)

The engine seems to be grounded well.

 

[Tom F&L GoR]

Final, regarding your DEX-COOL comment, you are relying on circumstantial evidence, and a small amount of it. You are using your title to speak from a position of someone who is presumably providing a technical service, and in this case, you should be a little more diplomatic... if you care about what people think of your advice.

DEX-COOL is not a specific brand or particular chemistry. It is a licensed symbol from GM that allows any coolant marketer that can qualify against their specifications to place the trademark on the container.

 

[SingleMalt]

You know, Tom's a funny guy in many ways. I've never EVER seen him offer bad advice and every bit he does give is very well thought out. Ever think of charging for your help, Tom? I mean, you must spend quite a bit of 'spare' time helping these folks out. Either way, it's always appreciated.

Mike

Final, regarding your DEX-COOL comment, you are relying on circumstantial evidence, and a small amount of it. You are using your title to speak from a position of someone who is presumably providing a technical service, and in this case, you should be a little more diplomatic... if you care about what people think of your advice.

DEX-COOL is not a specific brand or particular chemistry. It is a licensed symbol from GM that allows any coolant marketer that can qualify against their specifications to place the trademark on the container.

 

[Viper Specialty]

Tom- ***? Kettle? Black? Easy to point fingers when you werent actually a witness of what happened...and the 1000 bucks didnt come out of your pocket. Small amount of evidence? are you kidding me? 2 Vipers, both with new aluminum rads, both with prestone dexcool, both ruined by electrolysis. Both Vipers bought new Rads and switched coolants, Both fine since, no signs of electrolysis. Circumstantial? Once..? Maybe. Twice? I THINK NOT. Perhaps you should give a ring to Ron Davis and ask how many times they have heard the words "Dexcool" and "Electrolysis" in the same sentance? When I sent in my ruined radiator, that was the first question they asked me. "Were you using Dexcool?" "Yes" "Figures, we have seen an incredibly high number of radiators that were ruined by electrolysis and also were using Dexcool". That was all the evidence I needed right there, and no way you are going to convince me otherwise.

REGAURDLESS of Dexcool, I have since installed 15+ Radiators in Vipers using the above guidelines and Mopar Red 5-year. Havent had a problem with one yet...that is the coolant I recomend and will continue to use.

 

[Viper Specialty]

And you make it sound like I am abusing my "title"??? Like I have anything at all to gain from this post...? I am just trying to help the guy. Even if there was a 1 in 1000 chance that Dexcool could cost him additional money in one way or another, is it really worth it? Perhaps you would like to put a radiator on retainer just in case? If not, then let people speak their minds without jumping on them. I am not flaming you, but this isnt the first time you have jumped on me for speaking my mind on this topic, or others -specifically Accusumps- which are a completely "common sense" item. I have no idea how you convinced yourself to argue it, but oh well... thats off topic. I am in a bad mood today, and that insinuating post wasnt the first thing I wanted to run accross tonight while checking the boards... one thing I dont have a ton of time to do anymore, all I do is work on these cars.

 

[99 R/T 10]

I just installed an aluminum rad., but the pepcock is brass. Also, the line out to the reserve tank is brass. Will this cause the radiator to corrode? If so, where would O go about finding steel or aluminum replacements?

 

[Viper Specialty]

96 R/T- Yes, the disimilar metals will cause galvanic corrosion to occur relativly quickly. Aeroquip makes virtually any aluminum fitting you could need, though hose barbs in AL arent one of them, you would have to go with an AL AN3 elbow, and an AN3 ****** and screw them together. (If you dont have a store local, let me know, I can get what you need an ship it down to you) If you need a low-profile aluminum elbow, I can get them from Ron Davis, (1/8 pipe thread, stock sized ******), A little pricey though, like 15 bucks if I recall... I recomend using an aluminum elbow, and a steel drain plug. Aluminum pipe threads tend to bind up, so once its in, its in. removal will almost always cause damage. make sure you get it right the first time, lol. The steel drain plug however, will not bind with the aluminum in the radiator, and can be removed.

 

[Tom F&L GoR]

I have witnessed the opposite; hundreds (literally) of taxis, diesel tractors, and my own vehicles (only four of those.) Presented with some additional information, you still insist on an absolute condemnation, which I find technically unreasonable, and from your platform of Viper Specialty Performance, misleading. Ron found some pretty good stuff here:

http://vca2.viperclub.org/forums/showflat.php?Cat=&Board=UBB14&Number=384264&Forum=All_Forums&Words=dexcool&Match=Entire%20Phrase&Searchpage=0&Limit=25&Old=6months&Main=384194&Search=true#Post384264

DEX-COOL has been under fire because it was "new and different" at the same time as some OEM issues with gaskets, under-charging, and coolant supplements.

Traditional green stuff puts down a layer of corrosion additives on the metal surface very quickly after introduction, then has little protection left in the fluid. That's why it's necessary to change it periodically. DEX-COOL technology coolants don't put anything down until the chemical reactions of corrosion are indicated, so it provides better heat transfer (because there's no additive layer until needed) and why it lasts longer (not used up right away.) But if the system leaks or was undercharged, the "dry" part could rust or corrode because the DEX-COOL can't cover the area with any additives. You'll see this characteristic become the issue with all the GM cooling system lawsuits.

Given the Viper layout, it's not too difficult to imagine a little air left in the system. Maybe Ron David could comment on how many non-Viper radiators using DEX-COOL they've had problems with.

 

[Viper Specialty]

TOM- Absolute condemnation? I am only talking about VIPERS W/Aluminum Radaitors. Hell, my platform, VIPER Specialty Performance, even SAYS it! I really dont care about any other application in the world at the moment. Did you know that the temp sender for the Viper engine is Brass, screwed into an aluminum head--- one of the fundamental no-no's of metal-to-metal contact in an electrolyte? Do you think GM planned for the coolant to be used in that situation? I doubt it. How do you explain the first time I pulled a water pump off my car with green coolant, the water galleries were shiney aluminum color... and after dexcool, they turned dark brown/black? (Brown and black on Al means electrolysis) The fact that Dex doesnt coat anything could explain all of that. all of the anti-corrosion proporties could have been used up by that simple brainless move by dodge, in one spot, and nothing is left over to protect the radiator itself.

There are lots of tests for corrosion on Dexcool... but has any tested its proporties in an electrolysis condition? I havent ever seen anything. Electrolysis is a whole new ballgame, different rules.

 

[99 R/T 10]

But Daniel,
If the two dissimilar metals are seperated by say pipe tape or sealer, the metals never contact. So in this case, there shouldn't be any corrosion, correct?

 

[Viper Specialty]

Theoretically, you are correct... though it will never happen that way. threads are not "perfect" enough to prevent contact. even the smallest amount of contact will cause electrolysis. The reacton isnt caused from direct contact, it is cause by the electrolyte (coolant) which conducts electricity completing the circuit, in effect making a battery and electroplating your radiator. any type of electrical path between the two metals will induce the reaction.

 

[joe117]

Hey, about that sacrificial anode on a boat,

I think you use zinc on a typical boat with an iron engine, steel shaft, bronze prop and various bronze underwater fittings.

If you have an aluminum boat, like a Marinette, I believe you would want a magnesium sacrificial anode.

The sacrificial anode must be lower on the nobility scale.

Outboards are aluminum. I'm not sure but the anodes on them look like zinc to me, so zinc must work on aluminum but I know that magnesium would work better.

 

[joe117]

So the company that made the aluminum radiator said there should be no voltage between the coolant and ground.

Did they say what to do about it?

I believe the radiator mounting could have something to do with this problem.

Some radiators are shock mounted with no electrical contact to ground.
I can't decide if the radiator should be grounded or not but that is the only thing I can think of that one could do to solve the problem.

It's also possible that the probe you used to contact the coolant could cause a voltage. What kind of metal was your probe made of?

 

[Jack B]

I have a lot of below the waterline aluminum on my boat. The zinc's were not doing a good job. I put on magnesium anodes this year.

 

[Cris]

The Chrysler coolant is a HOAT Valvoline G05 (note other manufacturers produce this as well) type hybrid organic chemistry coolant. It contains some amount of silicates which coat and protect the metallic surfaces similar to the old green stuff. OEM testing with a true OAT coolant (such as Texaco Long Life coolant or Dexcool) was not successful in all applications. That is what lead to the development of the HOAT coolant. Use Dexcool at your own risk. My understanding (not a chemist) is that it is more sensitive to electrolysis and nucleate boiling related erosion.

 

[Robert1994]

Whew, you guys.....anybody that has worked with automobiles long enough has run into Buick and Ford engines that have eroded aluminum timing chain covers or intake manifolds. This was when most if not all domestic engines were made of cast iron and alternators or generators were producing typically 37 amps. The aluminum engine components that were exposed to coolant invariably suffered from some degree of electrolysis. As more and more engines are made of more and more aluminum, and alternator output has increased tremendously over the last several years, the damage has been much more wide spread and more apparent.
There is a product called Rad-Cap (I happen to be a distributor) that introduces
a sacrificial anode into the coolant (on my Viper it is attached to the
coolant bottle cap). It doesn't have to actually be on the radiator itself, just in constant contact with the coolant.The anodes are eaten away in about a year or so. They and similar products sell for less than $20.00. It's more
than just cheap insurance, you are saving your engine.

 

[HOdbleFman]

Does anyone know where I can get a sacrificial anode for the drain plug on my aluminum radiator. I just got the Fluidyne and it has a brass plug. I'd like to change it before I put it in my car.

 

[Viper Specialty]

I personally would not ever use one of those sacraficial anodes in a cars radiator system. On a Boat, fine... there is plenty of water in the sea. But, in a car, only a limited amount of coolant. Do you really want all that disolved metal churning around in your cooling system? nope. it is a band-aid fix anyway- There should be no reason to actually need it in the first place if set up correctly. Make sure if you decide to ground the radiator, ground it to the ENGINE ONLY. If you ground it to the frame, it becomes an electrical path to ground should the ground straps be overloaded/weakened/come loose/etc. Such a current flow can disolve a radiator in a matter of minutes. When grounded to the engine, it is given a ground, but does not become one.

VWMECHENGR- DID THEY ACTUALLY SEND IT LIKE THAT?!?!?!? If so, call them right away and ask them what they have been smoking! that looks like a blatent attemp to shorten the rad life. If it wasnt shipped like that, either way, get it out ASAP!

 

[red98GTS]

Ron Davis made a custom aluminum radiator for my early mustang recently. It came with an aluminum drain plug. I asked him about using a brass petcock instead of the aluminum plug to facilitate draining the thing when it came time to do so. He said don't do it.
Also, he recommended NOT grounding the radiator to the frame as I recall. Coolant and distilled water only, at a 50/50 mix was his feeling as well. This is a local Arizona company and he has been around for a long time building really nice custom radiators for just about anything. Nice work and I personally believe this guy has forgotten more about radiators than most people will ever know.
I also remember taking apart 289 Ford engines that people put an aluminum intake on, and the corrosion on the manifold itself where the water ports were was unbelievable. Don't know why I mentioned that but it just flashed in my mind. Sorry. Pete the ex glass guy.