What coolant are ya'll using?

[Z-train]

What coolant are you using?I just found this after less than 5K miles.

Has to be aluminum/coolant related.

[KELMO]

Thats just nasty looking. I use Nissan coolant (999MP-AF000P) mixed with distilled water. The tap water in this area is very hard and does the same type of crap like what you have there only not in that short amount of time/mileage. The Nissan coolant runs about 25.00 a gallon.

[Boaty]

You could use straight river water and it wouldn't do that. That looks like to me you had some sort of chemical in the coolant.

 

No antifreeze will cause that, either. You had some kind of contaminant. Judging by the color, which looks sort of rusty IMHO, I'd say you had something leftover in the block. What that could be, I'll never know. But if you made that mess in 5K miles, there's something wrong here.

 

You can run whatever antifreeze you want, personally I use Prestone if I am feeling picky but for everything else I work on I just buy the prediluted walmart stuff. (SuperTech). Never had a problem with it.

 

GM's use DexCool (orange) but even then it's just a long-life antifreeze. I think the OE stuff might have an anti-corrosive additive or something but I've seen people use pretty much everything and anything without a problem.

 

Now seeing as how the head is that gunked up, I can only imagine what your radiator looks like.

If I were you I'd start figuring out what you wanna do to clean it out... I am not sure a radiator flush is going to cut it here. Maybe a very mild mix of CLR and distilled water would help but everything it breaks loose has to go somewhere, which would be heater core/radiator.

 

Try and clean it up then backflush your heater core and take your rad down for a good cleaning.

 

PS that's nasty, worst I've ever seen!

[Boaty]

PS use distilled water or pre-mix.

 

I'd never run city-water, and if you have really hard (well) water it could corrode up after time. But that looks like chemical corrosion to me.

[Z-train]

I wouldn't use "Deathcool "in Obama's car.

This was a 50/50 mix from O'Reilly's.Someone mentioned that 50/50 isn't made with distilled water

[Boaty]

I've never had a problem with it personally but YMMV.

I ran Walmart 50/50 in my car for the last 3 years. Radiator was still shiny inside when I yanked it out for the KA-swap. (Can't say much about the crushed fins, thanks electric fan mount failure!)

 

Did you by chance ever run a coolant flush mix through it?

If you don't rinse out everything after you run the flush, it does similar things. But yours is like... somebody dumped wheel acid in the radiator or something haha.

 

Alternatively, last time you did a coolant flush, it could have broke some gunk up in the block and it finally broke out and spread to the rest of the engine. The rusty color tells me that something was corrosive in the block and made rust, or it was leftover DexCool.

 

I'm still voting for chemical corrosion though. I've seen cars running straight well water that sat in a yard for -years- and they never looked that bad... but it's a blessing in disguise, now you have an excuse to clean it out really well. :D

[DanielC]

"I wouldn't use "Deathcool "in Obama's car."

 

I would.

[pants]

I have straight water in mine right now, just because I was tracking down a leak. I'll go buy some Oreilly's brand stuff probably, we've used it in my dad's car for years without worry.

[banzai510(hainz)]

The Green stuff ,whoever makes it

do 50/50 mix

[Z-train]

[Spades]

ok, so there are some new coolants emerging, known as O.A.T.(Organic Acid Technology). These coolants started debuting with the introduction of Dex-cool. Before you start boarding the "I hate Dex-Cool" train, there is something you may not know about Dex-cool. Most old school OAT coolants and some Hybrid OAT coolants(HOATS) do not play nice with oxygen. While they are far superior, funny things start happening to it when you mix other foreign additives and Ethelyn Glycol products with them, but what really kills them is contact with oxygen(opening up your antifreeze bottle regularly to check coolant or developing a leak) or running them for longer than the recommended service interval.

 

GM had more problems than just with Dex-Cool. The real issue was the gaskets they used on their V-6's. The intake manifolds were plastic junk on most of them, with horrible gasket designs and materials that were eventually updated(Fel-pro redesigned the gaskets and offered a much better alternative to dealer gaskets for years before GM decided to do something about it). The entire cooling system was full of cheap cut-corner gaskets and plastic water outlets, and very prone to cracking in a short time. Combine that with the average consumers of their cars believing the whole "routine maintenance" idea was a scam, the coolant was destined to fail. The coolant has its problems, but the owner (along with some cheap-o gaskets and plastic parts) is really to blame...as soon as oxygen is introduced into the system the coolant starts a lovely path of turning into a mixture contaminated with iron oxide, and sludge's itself into a gooey mess.

 

HOAT's and OAT's are decent enough coolants with a very long service life, when properly maintained, they play nice with just about anything(plastic,aluminum,iron,ect.). I would not recommend them in an older car however, at least not Dex-Cool or anything using 2-EHA(2-Ethylhexanoic Acid) as an inhibitor. That is the stuff that becomes corrosive to gaskets(especially ones that aren't designed to withstand it), and on a cooling system like most Datsuns have, that could be bad, at the very least you can expect to only get 2 years and 30k out of a coolant service, and the added cost and no real benefits make it a poor choice to standard coolant. Once air starts getting into the system everything starts going downhill, and most datto's do not have a fully closed system, so Dex-Cool really is a poor choice for them...on a Chevy, VW, or any other newer car that has a closed system, it does its job as long as you maintain your vehicle.

 

With all that being said, I do not see anything wrong with running an extended life coolant in a datto, just make sure to get a HOAT coolant that uses a traditional inhibitor like silicates or phosphates. Eventually I am sure they will phase out green coolant, and everything will use HOAT's...in the mean time, some of the HOAT manufacturers still have a few additive bugs to work out when it comes to vintage machinery, so as with everything else in the automotive world, don't believe everything you read and stay on top of maintenance.

 

NOTE: as for the pics you posted, I am guessing whatever you used was just dye colored tap water and that your radiator cap is not holding proper pressure/getting stuck open(or you have a small leak somewhere)...because that is definitely corrosion from a lack of additives...lovely what happens when iron oxide and aluminum get together to play...and I doubt that without an air leak that even straight tap water would do that in 5k miles(it might, I just haven't seen anything that bad in so few of miles yet)...unless the car had been sitting for a long time.