mkgarrison5

DAMN, so you are saying that the 50/50 "works with any color" is a close cousing to the dexcool????

MTL_4runner

Yes, but read the side of the bottle. If it says contains phosphates or silicates, then it likely doesn't have any OAT in there at all unless it claims to be long life or have a long change interval.

The idea isn't that this OAT only stuff will suddenly blow up your motor for no good reason, just that I believe there are better coolants designed for use in your truck. It's also a free country so now that you have all the info, use whatever makes floats your boat. I had been running the Prestone Long Life 5/150 orange coolant in mine for about 2 years before I decided that I just didn't feel comfortable using it. So did my engine blow up or spring a leak? No.....but I'm not going to chance any future issues.

rdharper

I am in danger of learning something, so thanks for forcing me to read a bit.

After tracking down enough info, what I'm thinking is that you are right, PEL 50/50 is an organic tech. There is a lot of theory on cavitation and gel related problems. Also there have apparently been forumulation changes in the DEX-COOL spec to accomadate that potential problem.

Our worst problem in the 3VZE engine may be corrosion related, which seems to be best protected with the OAT spec. As to cavitation and/or gel related problems, that should show up as a temperature problem, which admittedly, many drivers might miss if they do not have high awareness of their engine temperature. The gel problem would show up as gel in the overflow, or on the bottom of the radiator cap. Those are checks I make periodically anyway.

In any event, I've learned something, and will stick with Prestone Extended Life 50/50 for the benefits of the OAT technology, while carefully watching for any signs of cavitation or gel. My bet is that I will continue to have the best of both worlds, ie: long life, best corrosion protection, convenience and price.

Thanks for the info. Feel free to add any other observations.

MTL_4runner

No worries, that's what YT is here for.
I learn new stuff all the time here too and it's not a crime last time I checked.

The good thing about OAT coolant is you can usually add it to other types too, so you could mix with phosphate or silcate based coolants to give you a bit more stort term and cavitation protection.

SteveD0603

Yeah, but now after reading more and according to Jamie, it looks like the red is the way to go! I'm gonna have to do this soon. It's got me worried now! Yikes!

rdharper

I believe many European "hybrid" formulations do just that. Silicate for short term and OAT type mix for long term.

So far (6 months), I've had rock solid temp control, nothing but clean coolant, and zero coolant added. Hits the hi and low mark on heating and cooling exactly as it should.

At the one year mark, I will draw out one gallon and replace with one new gallon of 50/50. At that time, I will check for clarity and gel components.

And report back on this thread, good or bad. It will need a bump by that time...

CJM

With all due respect if my truck, cars and any vehicle I have ever driven is fine I dotn care what Toyota says or the manual says. The manual also says the fuel filter is a lifetime part...so I only trust it as far as I can thrown it.

If my own mechanic who runs a pro street dragster runs plain old prestone and only flushes that car every 3 years and its fine then I dont see a problem running it in my truck.

deserttoy84

Well would prestone's version of "dex cool" be bad too? I think prestone would of "updated" there coolant so they arent liable either. Is the DEX COOL OEM coolant causing these problems? Either way its coming out for pink, but i odnt htink the prestone dex cool is THAT bad. It been fine a few cars we own.

MTL_4runner

Yes, you're exactly right.
That is what they call the hybrid OAT or HOAT type coolant for short.

MTL_4runner

I think you're getting caught up on brand names rather than focusing on what the chemistry is and how it works. All the current "long life" coolants that I know of use a form of OAT protection. This protection may be augmented by turning the coolant into a HOAT most often by the addition of silicates (as you'd find in something like a G-05 coolant). Part of the confusion is that Dexcool is a standard, not a brand name like Prestone or Zerex. To the best of my knowledge, the "Dexcool" OAT only type coolants (whether it's made by prestone or some other brand) still have issues with short term protection and cooling system cavitation. GM clearly had issues running the original Dexcool in its vehicles, but I suspect that if they are probably going to address this in a new version of the Dexcool standard. It sounds to me like they may now be turning it into a HOAT type coolant instead, but I guess time will tell.

MadCityRich

For what it's worth:

I had a coolant flush done at my local dealer. They put green coolant in the 4Runner to fill. With other Toyotas they used pink (my old '95 V6 PU). I think it's all the same stuff.

Color really doesn't matter. I've got blue stuff in my BMW (256k miles on that engine). What you need to check is the side of the bottle and make sure it says it's OK for aluminum. For most coolant on the market, this is the case. There aren't too many engines out there without a good amount of aluminum anymore.

The bigger issue is making sure your coolant stays fresh. This means flushing every two years or so. Acids build up and can start to corrode things otherwise.

It doesn't matter if it's ethylene glycol or propylene glycol. Propylene glycol is less toxic and has a slightly lower heat transfer coefficient. Everyone says Dexcool sucks, even GM. So stay away from Dexcool.

If your coolant is aluminum safe and isn't too old, then don't worry about it.

MadCityRich
2002 4Runner Ltd