Steve Cattaneo

Information for those who may not know your 928 aluminum engine requires special love and affection.

Another potential problem with aluminum engines and/or radiators is electrolysis (the decomposing of a chemical compound by passing a electric current through it). Aluminum is especially vulnerable to electrolytic corrosion. The coolant is part of the engine, so some current flow through it is almost inevitable. Because of the grounding system, the 928’s are more prone to electrolysis. Probe the coolant; if you get a reading of .1 volts or higher the radiator and engine is a prime candidate for over heating (sounds familiar) from corrosion build up. You will always have voltage in a coolant, .5 volts or lower is tolerable, anything higher and electrolysis will eat away at the aluminum. Any boater knows about aluminum corrosion that’s why boats have anodes to draw current away form the aluminum out drives. The common cause of electrolysis is poor grounds. Electricity will always take the path of least resistance. If you add horns or lights to your 928 or to any car for the matter never ground them to the radiator mounting brackets. To minimize the potential danger or electrolysis run extra ground cables from the negative post of the battery to the engine, run an extra ground cable from the engine to the frame on the driver’s side. I took a small anode, tied fishing line to one end and a cork to the other end, dropped it in my expansion tank and I change it once a year.

Antifreeze formulated for North America vehicles are generally different from that used by the European and Asian vehicle manufactures. European vehicle manufactures typically specify an additive package that contains borates and low silicates, but uses no phosphates, because hard water can react with phosphates to form calcium and magnesium deposits. The Asian carmakers, on the other hand, generally specify an additive package that uses phosphates, but no borates and low or no silicates. They don’t want borates in the system, because they believe borates can corrode aluminum if the coolant is neglected for too long. Most antifreezes’ (with the exception of the extended life OAT products) for North America applications include silicates to protect aluminum, plus phosphates and borates to protect cast iron.

Porsche recommends that only approved phosphate and propylene glycol free antifreeze, such as Autobahn and Mercedes Benz, or Zerex Extreme 450 be used in their aluminum engines. The models affected are 924’s, 944’s, 968’s and 928’s. If you don’t know for sure what’s in your cooling system have it flushed and refilled with a 50/50 mixture of approved antifreeze with distilled water only. A higher then 55% volume of antifreeze concentration sound be avoided. I change my antifreeze every 30,000 miles or 2 years, which ever comes first. It’s cheaper then replacing the radiator or a leaky head gasket due to corrosion.

Good Luck
Steve C.

Nicole

Thanks for your detailed and very interesting writeup! Shouldn't we be able to rely on our 928 mechanics to fill the right stuff into the system?

Can you further clarify, why the antifreeze should be mixed with distilled water? Does distilled water have higher currency resistance?

When you refer to adding additional lighs (and horns), are you talking about those red and blue ones that should go on the roof of your beast? ;-)

Funny, that you talk about "electrolysis". I had only known this as a painful cosmetic procedure for permanent hair removal. Now, if the 928 engine has electrolylsis, too, is this the ultimate proof that it is female? Hmmm... I wonder, if we'll ever figure this out! ;-)

Jay Wellwood

Nicole-

Using distilled water ensures that the minimum amount of free ions are available - thus minimizing the potential for electrolysis (or current flow).

Another benefit is that distilled water also minimizes the introduction of non-water contaminants.

hth-

Jay
87 S4 Auto

PatrickP

Thanks, Steve. This one is definately a keeper. Shortly after I purchased my shark, I thought that, among other things, I would have the coolant changed and would save a few $$$ by buying my own at the local Pep Boys. Fortuantely, the mechanic knew what you know ( and I do now.) He put in the right stuff. I gave the other stuff to my neighbor for his Ford.

Steve Cattaneo

Nicole,

The reason why distilled water is used is because it has fewer minerals (iron, zinc etc.) Different metals when combined can cause a chemical reaction, which also corrodes. Distilled water has currency resistance because it has no minerals.

928’s are multi gender. They take the gender of their owner. That’s why yours is female and mine is male. ;- )

I could never figure out why females will go through all this torture (electrolysis, waxing) just to look beautiful. Why don’t they just go
“NA…. TU…. RALLLLLL”? ; -)

California is not that far from New York so don’t be surprised if you find “The Great White” and I parked in front of your house tooting “His” horn and flashing “His” lights. ; -)

Steve C

The great white

Nicole

Well, from now on I will never ever fill regular water into a radiator again (not sure, if and when I did that last time, but anyway...). Thanks for the info!

Steve, it would be quite intersting to see your 928 flashing it's ligts in front of my house. I wonder, how my grey shark would respond. Maybe it would blink it's retractable eyes and smile in a kind of shy way...?

Just a warning: the Saab might get jealous and start an oil fight! ;-)

It is very protective of the grey shark, and makes sure it never has to get out in bad weather...

LarryM

My girl friend always thought I was crazy for buying my car bottled water, so did the grocery clerks. That's ok I saw what they drove
I have also added RedLine's Water wetter to my 928's since 93 and have never had a problem. I do flush mine every 30K when I replace the Belt and water pump.
Does anybody have anything good or bad to say about water wetter. I run it in all of my vehicles.
When it Rains here the Z71 gets pulled out.
FYI, If you do get caught out in the rain,, the 928 does drive nicely in a 3 inch an hour downpour. Over about 60 your wipers aren't needed. New Tires are a given.

DaveW

watch out using bottled water as this usually = mineral water. Which is exactly what you want to avoid.

IIncidentally I also learnt this with my carniverous plants which also need pure water just like the ally engine, using bottled water deposited too many minerals to keep them healthy.

Cheers
DaveW

dr bob

Larry writes:

> Does anybody have anything good or bad to say about water wetter. I run it in all of my vehicles.

Yes, to the good. My test platform is my aging '92 Explorer. which does limo duty in the summers with the boats or other towables attached. Drive from the L.A. basin to Needles or Laughlin to play, in summertime temps fo 120+. With Water Wetter, it can sit at idle indefinitely with the AC running, needle gets to half scale. Before Water Wetter and same conditions, ten minutes to overheat. These conditions are about as extreme as you might subject a car to, and it's a testamemnt to Water Wetter. I'm a very satisfied customer.

The Explorer gets very regular services, with the extended life coolant (don't use Prestone Extended Life!) changed every two years or so, with distilled water since new.


928 Gets the same treatment as the truck. The needle moves around a little in traffic, but no worries at all. The needle touched the right mark, the white one below the red heated mark, only once since the treatment, and that was in 100+ temps climbing the Grapevine hill from the north on a 110+ day, cruise set at 80. That's also the only time I have had the fans stay on after I stopped, this time at the rest stop at the top. A couple minutes later when I returned to the car, fans were off, and so was I. I love the stuff.

Steve Cattaneo

Larry M,

A 95’ 928GTS, the Cadillac of the 928 family. I will trade you my 85 928SEURO, my 1967SS Chevelle for your 95’ 928. I am also working on a XJ6 Chevy motor conversion; I will even include it in the deal.

When you do your 30k service, include the t-sat and change the rear seal in the t-sat housing. It’s very important. It seals the engine coolant from the radiator coolant.

Dave W makes an excellent point, bottled water is not distilled water.

Distillation will kill and remove bacteria, viruses, cysts, as well as, heavy metals, radionuclides, organics, inorganics, and particulates. And yes, it will remove minerals, which fall under inorganic contaminants.

Patrick, I’m glad my post helped you.


Steve C
The Great White

John Struthers

All concerned,
Electrolysis: The breaking up of tumors/hair roots, ect. by electric current.
Or, the chemical decomposition caused by
electric current.
Electrolyte: A solution that conducts electric current, especially in cells/battery's.
Electrolytic corrosion: BAD NEWS!!!
Remember that Hawaiaan Airliner that went cabriolet in flight? Yep, electrolytic corrosion. Started around the faying surfaces of the rivets then worked its way down the rivet line including nearby adjoining rivet pitches, attached stringers and formers and bulkheads. It also goes by the name of FRETTING CORROSION - looks like the dry, wrinkled back, of an old persons hand -. Once it starts developing it spreads exponentially, particularly, where disimilar metals, or, even similar metals with different properties meet. Depending on other factors it can etch even .080 -thousands- aluminum to the point of failure in months or less. On aircraft the metal should be pickled, primer washed, primered, and when joined should have either barrier tape or Pro-Seal applied to joining surfaces to prevent the problem. The explanations provided by posters, though simple, should be taken very seriously!
And for the Coastal residents; there is salt in the air folks! You get used to it and don't notice it much but to 'outsiders' we can smell/taste the ocean as far away as El Centro from San Diego, and Modesto/West Sacremento from San Francisco. Let's see,
add salt to water and what do you get... I'll give you a couple of minutes. Basically, coastal sHARk owners will probably have more electrical problems, sockets, connectors, junction blocks, ground straps......... Please do youself a favor and change out those straps. Not being a professional spark chaser -so this is just a hunch - rather than add a second ground strap to the driver side I would add a second one to the Pass. side if for no other reason than co-locating would ease removal.
For the Battery: I'm going to notch the battery cover and go with a much heavier cable, haven't, yet, examined the starter ground. The zinc anode is an excellent idea and I believe Performance Parts sell an electrode pronged radiator cap for our 928's. I use distilled water for every thing. Windshield washer, battery, radiator. Its common sense -once you have the facts-to avoid adding contaminants to a closed aluminum, fluid system with electricity running thru it. Point of fact; in Texas the water is so bad if you go fishing the Game Commission posts advisory's on roughly 76% of all counties " DON'T EAT THAT FISH!" You would be suprised if you checked the water quality of your local area on the net for hazmat. Heavy metals and strange mineral, organic matter abound. Due to normal wear and tear of dissimilar engine and tranny parts there is enough crap floating around in your baby's circulating system without adding to the problem. As for me I'm a inveterate hand polisher so Pattycakes and I look a little like the Back to the Future DeLorean with blue static bolts of electricity arcing everywhere - the cats hate me -. Will this kill the Brain? Only the Shadow and sHARk Guru's know for sure...
Later
Keep em' rolling.
John S. & Pattycakes

dr bob

John:

You wrote:

"Point of fact; in Texas the water is so bad if you go fishing the Game Commission posts advisory's on roughly 76% of all counties " DON'T EAT THAT FISH!" You would be suprised if you checked the water quality of your local area on the net for hazmat. Heavy metals and strange mineral, organic matter abound."

Not wanting to sound --too-- sarcastic, but:

Plenty of the towns I've been passing through here in your state have signs up that proclaim "Superior Water System." I'm trying to figure that one out, especially since the water tastes pretty bad in more than a few of those places. Seriously, is this some sort of bragging right that goes on here, or is there some real reason why a water system is branded "superior?" Does this relate to the quality of the pipes, maybe? Maybe the system is made with special non-reactive lead pipe so it will survive the more conductive components?


Why do electronic gadgets come with semi-conductors? For the price, higher-end stuff should be equipped with real conductors!

Why is it that tornados only tough down in mobile home parks?

I have all these questions....

Nicole

I think, until recently the Texans had a governer who REALLY cared about pollution.

My question: Why does Houston supposedly have the worst air quality in the whole country?

Joe R

I have been using "water Wetter" in my car for some time. I never really seen a difference on the gauge but who can because they are so inaccurate. Like to think it helps the car in the Mississippi Heat. What do Ya'll think about "Swamp Shark"? for a name.
We have good air here, brown water and big Gators. one silver 78, one red 83 and one bronze 82 (for sale).
SHIPS OF STEAL GUNS OF BRASS, WE ARE THE ONES WHO PROTECT YOUR A--. Go Navy!!!!!

Ed Ruiz

Dear felow sharksters:
I've been using distilled water and Phosphate and silicate free coolant since I bought my first 928 12 years ago. There are now several American brands of coolant that are Phosphate free and only one the is also silicate free (Quaker State). Ten or so years ago, the only coolants available (that were both) were made in Germany. Fortuantely, times have changed. (BTW, if the water pump has a metal impeller, the use of silicate free coolant is not that important. However, if it has a plastic impeller, then you should avoid using coolants that have silicates.)

I tried "Water Wetter" for a couple of years. Based on my limited experience, I don't think the product did much good (or bad) for the 928 cooling system. I stopped using it a few years ago, and the engines ran just as cool without it as they did with it. (Go figure.)

I would recommend replacing the coolant every two years (regardless of mileage). BTW, don't forget to flush the coolant from the engine (the block has two drains). Also, replace the coolant pressure cap at the same time you replace the coolant hoses (every five years or so). BTW, as a matter of routine, replace the water pump every time the timing belt is replaced.