Re: What's the difference between Toyota, Nissan, and Honda antifreeze?

UNLESS the mechanical seal is faulty, coolant does not come in contact with the shaft bearings!

Here's the short story:

Japanese manufacturers typically recommend no silicate antifreeze. Apparently, as the story goes, the silicate can wear the seals and cause leaks in the WP. Maybe they just make lousy seals, I dunno.

Prestone green is *high* silicate. It is the *opposite* of what you should put in a Japanese car. Prestone introduced their high silicate blend in the 70's as a cure for corrosion problems. More silicates, less corrosion. I would not use Prestone in Jap car.

Valvoline sells a coolant called G05. It is _low_ silicate (not silicate free) and has other corrosion protection chemicals. It has been in use in Europe by Mercedes, Saab, and others for many years and has proven out well. Ford and Chrysler have recently adopted it as their new coolant.

GM has been using Dexcool by Havoline (Texaco). There have been some serious issues with Dexcool. It's apparently fine in a perfectly clean system and goes the 5 years. However, it there is _any_ contamination, you get corrosion in new cars - some only

2 years old. Contamination includes leftovers from GM's "stop leak" that is run through at the factory (in new cars, imagine that) and from air (yes, normal air) in the system. There are lots of claims and suits against GM. Some folks claim that the Dexcool product it self is contaminated out of the barrel. FWIW, GM is rumored to be changing to another manufacturer this year. It is also silicate *free* but has issues. Do a web search if you like.

So, what to use ? Use Jap coolant to be safest. Use G05 with a simple water flush to play it a little riskier with a low silicate product. Use a Dexcool product with a serious flush if you want to go higher on the risk scale with a no silicate. (Personally, if I was bent on _no_ silicates, I'd just buy Nissan coolant and avoid the risk of Dexcool like coolants)

Bob

Then please explain what the problem is, as many people say, with coolants that have those chemicals in them? Or is that just another urban legend.

John D.

It's not quite as simple as that. The origins of the variations between the Japanese and European cars can be traced to water quality. In Europe the water is predominantly hard. As a result of this, they typically have a formualtion from the factory that can accomodate some "hard" water without degrading the corrosion inhibitors too much. The Japanese formulation does not accomodate hard water and distilled water is recommended. The problem with Dexcool is not a "clean" system issue, it is a precontamination with silicate issue. Dexcool works by allowing an initial corrosion that subsequently protects.Dexcool takes quite a bit of driving to become effective - approx 1,000 miles. Silicate works by deposition over the metal and plating - This process is a much more aggressive one, and is instant. When you convert and try to flush out silicates, you will not get all of it out. If the silicates are still active and plated on the metal , you get silicates actually neutralizing the Dexcool. Thus you get no Dexcool protection and then the silicates are worn out. This leads to no corrosion protection - on one flush and refill.

If you convert to Dexcool, do flush, install Dexcool. Drive 1,000 miles, Flush again and install Dexcool. You will find that many people who have problems with Dexcool after a conversion did not flush a second time and reinstalled. A single flush will not do it. Also once some silicates get in there, you ideally need to flush twice again.

The problem with silicates is that they rapidly deplete and must be flushed out periodically or they gel and cause problems. Honda coolant is supposed to have "organic" protection which I suspect is Dexcool related. The big difference is that they don't claim long life and Dexcool should also be treated similarly.

Maybe silicates contribute to wear and then maybe a film of silicate acts as a "lubricant" in the stricter sense of the word. Hmmmm.!

For many years with my old Datsun, the standard routine would be to do a chemical flush and refill with Prestone, then add a can of water pump lubricant...hoping to take care of both corrosion AND the water pump at the same time. Lately, I haven't seen those cans of water pump lubricant around anymore.

John D.

Honda sells their own water pump lubricant though I'm not sure who makes it for them or if they make it themselves. What's interesting is that I had someone at a dealer parts counter deny that this was true even though I've actually seen the stuff at an independent Honda shop.

Eric doodled aimlessly in news: snipped-for-privacy@spam.now:

I don't know about "water pump lubricant", but they certainly do sell their own coolant. I have a gallon jug of it in front of me as I type. All it says on it is "Distributed by Honda Canada. Made in USA".

Just remember, clothes make the man, naked people have little or no effect on society.

Just because I am from Hartford I will plug this

IIRC, the water pump lubricant I used were made by Prestone...in those small yellow cans. But as I said, I haven't seen them lately...definitely looked for them at Autozone recently but they said they didn't carry them anymore.

I think Zerex makes one though...don't know about Nissan.

John D.

Honda Water Pump Lubricant P/N 08798-9005 H/C 4212049

Eric doodled aimlessly in news: snipped-for-privacy@spam.now:

I stand corrected.

Agreed, but that doesn't account for cooling system corrosion in 2 year old GM vehicles that have never had any coolant added. These are suffering from either impurities in the cooling system right out of the factory (GM admits to some of this), contaminated coolant right out of the barrel (GM admits to some of this by planning to change to a new carbo formulation from someone other than Texaco this year), and from consumer introduced contamination including plain old "air".

Bob