This is NOT how I hoped to start my vacation!

The water pump failed on my truck yesterday. Why are there so many different varieties of coolants?! For decades, cats and trucks managed just fine with regular old green antifreeze. Then GM started this dex cool nonsense about 30 years ago, now the coolant section at the parts stores look like the oil aisle. Every automaker has their own brand, color, why?

My Ram takes HOAT coolant, which is an acronym for Hybrid Organic Acid Technology. The Napa store where I got the water pump was out of stock, autozone carries their own brand that’s supposedly compatible, it took a couple stops before I could find the correct stuff. I seem to recall the same issue last time I did anything with the cooling system on this truck.

On an unrelated subject: it’s pretty damn hot and humid today!! Of course, my truck is too big to fit in the garage. I’m servicing the water pump and driveshafts in the driveway. Blah.

 

Ethylene glycol is corrosive. Coolants have additives to prevent that. Different additive packages for different expected materials it'll come in contact with and different service life intervals.

 

The diesel engine in my 86 F250 needs coolant with Supplemental Coolant Additives (SCAs) to prevent cavitation of the block. I added an auxiliary coolant filter.

https://www.oreillyauto.com/detail/c...ter/wix0/24073

 

I understand the additives don’t last forever, which is why occasional coolant changes are needed.

I’ll admit, until you pointed out different materials I failed to consider all the plastic parts on modern vehicles. Maybe old school green coolant does t play nicely with certain plastics.

Now I’m kinda curious, are there any coolants that absolutely can’t be mixed? Let’s say your 10 miles northeast of nowhere and need coolant. Are there certain combinations thst if mixed, will turn your radiator into a botched science fair volcano experiment?

 

Interesting. I was unaware of the cavitation and errosion problems to cylinder liners

Maybe the chemist and engineers really do know what they are doing!

Having said that, it seems they could streamline the different coolants, not every automaker needs its own proprietary coolant.

 

Use water. It mixes well with everything. .

 

Preferably use distilled water, if possible. Most, not all, coolant manufacturers recommend better water than tap water. Valvoline has a couple you can mix with tap water, but why take that chance?

 

Why won't this work? Just go to the auto parts store and buy this. Look what it says on it. "Guaranteed for ALL VEHICLES. Makes, models and years." What's to argue with? Prestone is not some off brand.

If you read the back side, which I don't have an image of but which can be read at the Autozone website, it indicates everything it's compatible with, and HOAT is one of them.

 

And on the road, use a pre-mix. It'll save you from having to f*ck around mixing in distilled water.

 

Of course they do. Gotta make a buck! 🤑

 

Or you could just mix the concentrate in your garage at home and put some in a used coolant jug and take that on the road. I do this all the time. I don't like buying the premix because it just seems like you're paying for water.

If it's an emergency and I have no alternative, then, yes, I'll buy the pre-mix. But if I can plan ahead, I'll buy the concentrate and mix it myself.

 

In our body shop we only used OEM coolants from the dealer. No chances taken of incompatibility or someone coming back in 5 years with a bad head gasket looking for a payout. Even then you have to double check because you don’t know if the parts guy picked the right coolant. Just went through this a few weeks ago with ATF for a late 90’s Lex/Toy where Toy dealer sent the latest version ATF that is incompatible with the earlier fluid that the car used. Trust but verify.

IMO one can play coolant roulette for convenience or to save a buck, but is it worth it if one tends to keep vehicles? Our dinosaurs are easily fed & watered but modern cars can have modern problems playing mix & match.

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Exactly, Daughter's Edge had the Ford Orange. Used this exact stuff in a coolant change plus just threw in some additive to try to prevent the internal water pump failure. My Challenger has the Pink, threw a shot of this stuff in, down slightly. Using this when I change the heater core in the Dakota. One and done, I have seen first hand what green mixed with Dexcool, turns it into clay, not good.

 

Its not just plastics (and rubbers). Different alloys consist of different elements that may or may not be compatible with your additive package. Different brazing or gasket materials also come into contact with the coolant. Even if they are compatible on their own, different materials in the cooling loop with one another can cause galvanic corrosion (e.g. copper and aluminum). To make matters even worse, some things are perfectly compatible in the short term or at room temperature, but break down over the long term or high temperature.

As with pretty much everything, the additive packages in coolant are a compromise to get the best results with the least tradeoffs. But there is no perfect additive package. Just like there's no perfect camshaft or intake manifold. Its all a compromise.

 

this is an issue known for years,back in the early 80's my buddy's international tractors had coolant filters with a membrane in em.after so many hours the membrane would break and release addatives into the cooling system to prevent cavitation.filters came in black and white.so say this year you put black ones on,next year white,this was a way to make sure you changed em.

 

Because buyers want to not have to do anything to a vehicle for 100k miles or more AND the automaker wants you returning to the dealership to have it serviced or at least to buy the coolant.
The old green stuff was 24 months and drain and replace. 98% of Vehicle owners rather not having to do that or have it done every 2 years.
The OEm's make different coolant to also void warranties if you just dump any old thing in.

 

Because of this situation, I added a coolant filter with the additive in it to my 7.3 idi, along with using the factory specified “special” coolant. Sold it years later to a friend and it’s still happy as a clam. Of course it has barely over 50k on it, but I don’t know that sitting does the system many favors either.

In other news, I was just reading a thread on a Chevy sight where guy posted pics of the worst gunk I’ve seen in a cooling system. Coolant Lives Matter!




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Holy hell, that might actually look worse than the mixed Dexcool and old green coolant! Curious what the hell he mixed together?

 

Short version: When in doubt, distilled water for the time being. Buys you time to locate your precise coolant at a reasonable price (Amazon, etc.)

 

When I owned a Mini Cooper Countryman S All4, the coolant HAD to be the manufacturer specific coolant (no water) or it would corrode a sensor tab out of the thermostat housing. Causing a CEL for the cooling system. That was over 10 years ago now and an aftermarket thermostat housing was almost $200. They're less now. Thing looks like an artificial heart.

 

I recently swapped O4B intakes with a friend to help him out. The intake he had developed a leak. When I got it you could look at the areas where coolant touched and it was super, super coroded. It wasn't cracked, it was perforated due to something in the coolant. I didn't get a picture but it's still sitting on the table up in MI and I'll get my nephew to snap a pic next time he is at the shop and post it. Another nephew did a great job of welding it up. So, I suspect that coolant type does matter....

jerry