Coolant and ATF fluid changes on Toyota

Couldn't this be solved by a well-place Heli-Coil or two?

The head can't be *too* hard to remove and replace. If you even have to...

Ford Windstar 3.8L with plastic intake.

Ford solves the problem of the rear bank of cylinders loosing the gasket on this model, then they install a plastic manifold.

Here in Mass we have mandated Ethanol in the fuel.

Seems the plastic Ford used in the early days didn't get along with Ethanol very well...

Told ya! ;p

Or changing head gasket material in mid-production...(7M-GE and asbestos HGs...)

I'd prefer to use T-IV (or 3309) since it is correct for the application. All of the miracle ATFs out there seem to indicate that

*they* "recommend" them for use in virtually every transmission ever created. That's not good enough for me or my customers. Realistically, I do agree that their synthetic product is probably protective, durable, and friction modified enough for satisfactory use in T-IV applications, but why take the chance? For a $2 per bottle savings?

My experience seems to differ, but maybe I'm not as observant as you are (sarcasm not intended). I find the T-IV in "Super ECT" trannys to get darkened by friction material as fast as the A series trannys used to. The fluid still appears to remain in great shape (though dark) as long or longer than the old A series with D-III though.

If you take care of it then your goal shouldn't be a problem.

Yes, the intake is plastic. That's an interesting theory that I can't shoot down, but would suspect it is grasping at straws. The most obvious and certain contributor to pulled head bolts was the early blocks with no threads at the top (deck) surface. On these problem engine blocks Helicoils can be installed, and their serviceability is excellent. It's a little tricky to get the HC tap that deep, but a standard tap can be modified with an extension and a little welding.

No Lexus has a xAZ-FE engine, let alone a 4 cylinder (US destination) so this particular instance is total apples and oranges. Any engine could suffer loose head bolts, due to design or previous installation issues.

Nutz. Thanks a LOT, John!

(Not mine...)

"Results of industry standard tests of the new Toyota extended-life coolant now show a substantial weight loss (corrosion), both in a 50-50 mix and in a 33% coolant mixture (solder corrosion is much greater in this more diluted solution)."

Read the article from Motor.com, among other excellent articles there, Aug 2004, and learn about things such as the 2EHA acid and its challenges to poorly designed cooling system:

I recall reading something about 20-30 times acceptable level (which is 1mg/cm^2/week). Been Googling but couldn't find this particular article. So yes, under perfect circumstances you can lose 1mg of metal per cm^2 per week!! "Slowly but surely".

I personally would prefer Mobil-1 over the reportedly excellent Amsoil or Redline or Royal Purple. Because Mobil-1 and 3309 are both made by Mobil. And I think Mobil uses its own additive package.

Valvoline primarily uses excellent additive packages from Lubrizol. People say Shell and Warren Unilube (Walmart SuperTech) use that as well (not sure). And IMO Valvoline has an excellent product line. Amsoil probably uses an additive package by somebody -- maybe Lubrizol, Afton or Oronite (Division of Chevron). Companies can buy synthetic stock, mix it with an additive package and sell it.

I don't think there is a need to flush ATF (but you should not mix different coolants). As for mixing ATF: "Mobil 1 Synthetic ATF is also compatible with conventional ATFs."

You can actually call Mobil up or email them on their "Ask Mobil" section about Mobil-1 and 3309.

That is quite correct. However, the ATF should be synthetic blend or synthetic to reach that interval (100K).

For conventional dino fluid, max life is like 30-60K miles (severe- normal service). But you also have to account for particle loading of the fluid. That's why for Dexron II/III severe service Toyota listed it as 15K miles for the Aisin A series transmissions without a decent filtration system. The fluid may still be good, but there are just too much crap in it.

However, I think Toyota's "lifetime interval" simply means the ATF's life is up when your transmission craps out. Really!

AERA-Engine Builders Association reported the following:

"The following information concerns the loss of coolant on some

2002-2006 Toyota 2.4L, 2AZFE engines. The location of this condition has been noted at the rear of the engine where the cylinder head bolts to the cylinder block. It has been reported that stripped head bolt threads have been found on some of these engines during tear down. When the two rear head bolts lose their clamping ability they allow coolant to seep out at the rear of the cylinder head."

More and more newer transmissions, especially LePellitier designs fill like manual transmissions. One drain plug and one fill/inspect plug.

You also have to make sure the temperature is within a certain range.

I'm not sold on an oil simply because it is touted as "synthetic". It's a buzzword at best for products sold in the USA. I even have a hard time believing that the best, highest quality base synths are really orders of magnitude better in terms of durability than conventional.

Couldn't agree more. Also, none of the filters I've taken out of any Toyota are anything more than a screen, which basically traps catastrophic chunks from going into the pump, but does nothing for particulates of friction material and tiny (normal) bushing/steel wear particles. In terms of filters and servicing, I like the domestic transmissions for their fiber weave filters. They sure seem to last a long time if you service them (and a really short time if you don't) despite the many pattern failures virtually all domestic trannys suffer form design inadequacy.

You know that's the case when every interval of the maintenance schedule for ATF reads "inspect". 420,000 miles? Inspect! Oh, the unit failed? Replace!

That goofy setup is the worst I've ever seen implemented. You have my condolences :-)

same time; it appears to be coincidence that these two design features are shadowing each other. GM has been offering "sealed" (I prefer dipstickless as it is more accurate but awquard to say) four speed transaxles for quite some time now.

MNo kidding! You can't get it from the top, so you have to get under the car (heavy-duty ramps and a creeper) and reach your hand up over and around a couple things, take it off, go above and get a LOOOOONG funnel, and then reverse. Time to punch an engineer in the nose!!

Built_Well wrote:

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John, that's a great article, but the reason the Toyota extended-life pre-mix pink coolant showed "a substantial weight loss (corrosion)" in the lab test is that the test was performed on radiators and heater cores made of * copper brass * and which used lead solder (in other words, old-fashioned, cheap radiators and heater cores).

I don't think the modern * aluminum * radiators and heater cores that Toyota uses, for example in the Camry, have any copper brass and lead solder in them at all. Ray O can correct me if I'm wrong.

Regarding the 2-EHA acid that GM's DexCool uses, Toyota is staunchly opposed to using 2-EHA in coolant. The 2-EHA is also not fast-acting. The article states that 2-EHA is "very stable and lasts a long time" but it "takes thousands of miles to become fully effective in protecting coolant passages." It's actually the phosphates that are used in Toyota's coolants that are fast-acting, not 2-EHA. According to the article:

"Extensive Japanese tests have shown phosphates to be a good corrosion inhibitor for aluminum, and particularly effective in protecting water pumps from corrosion after cavitation erosion/corrosion."

Sorry, Ashton. The ethylene glycol or propylene glycol can oxidize, in time, upon contact with air or oxygen, especially at higher temperatures. Reaction by-products are acids like glycolic, oxalic.

This is one of the reasons that coolant formulations have an alkaline buffer.

In this type of situation, that is true. The National Association of Corrosion Engineers defines corrosion as any process which results in the deterioration in properties or strength of a material. Manual processes such as erosion are included even though these are not electrochemically driven.

It could be disastrous to have galvanic couples between copper or brass, and aluminum.

There are a lot of problems with the organic acid inhibitors. Protection of aluminum can be an especially difficult problem, as DexCool users found out. The Hybrid OAT technology reintroduces silicate, at lower levels than in the green formulates, which was one of the few efficient inhibitors for aluminum.

Phosphates or phosphate esters can work miracles in some systems, particular where steel is involved. And, it doesnt take much to do the job. I havent tested some of the newer phosphate ester chemistry against aluminum, and cant comment.

I'll accept that as true. However, it's a moot point since whatever you do that wrecks the glycol is going to wreck the corrosion protection way before the loss of glycol becomes a problem. Which brings it back to my point, you should go mostly by miles, with time a secondary consideration.