DEX-COOL, Conventional Green, & G-05... My Experiences

Could have swore a local mechanic told me that once. I'll ask him here in a few days. If he says that is true, I will ask if he knows of a vehicle that does.

BTJustice

"Buford T. Justice"

Yes, but that pressure is not caused by steam, but by the liquid trying to expand when heated. A liquid under pressure caused by heating is trying every thing it can to boil, but because of the enclosed space, it can't. "Buford T. Justice"

Except that it ISN'T. Any residual minerals have the potential for screwing up the corrosion inhibitors in the coolant OR precipitating out and clogging the radiator. Hard water (calcium) typically doesn't upset corrosion inhibitors and in fact my help inhibit corrosion by keeping the pH high... but it also precipitates out. Sulfurous water won't precipitate out, but tends to lower pH and override corrosion protection. Iron precipitates and "binds up" some of the corrosion inhibitors. Chlorine and amine added to municipal water are corrosive to iron engine components. Basically, any impurity commonly found in north American tap water is at best a non-helpful thing to have in the coolant.

The safest course of action is to flush with hose water, drain completely (including the block drain plugs), and fill with a mix of distilled water and antifreeze.

Nice answer to a question that was never asked.

Let me re-phrase: Name one car that pumps engine coolant back to the transmission BY DESIGN.

Of-frickin-COURSE antifreeze can get into the transmission when the heat exchanger in the bottom of the radiator fails, everyone knows that! The original claim was that some cars have a heat exchanger in the transmission which recieves engine coolant from the radiator, rather than having the heat exchanger in the radiator where it recieves oil from the transmission. I don't believe I've ever read about such a design and I've CERTAINLY never seen one, and I asked for an example.

Sheesh.

Slicknick wrote:

transmission. In this case,

radiator coolant is

See the part where I said "a fixed pressure" in the quote below?

See again the part about "a fixed pressure." Real-world radiators operate at a fixed pressure limit (say, 15 psi).

. I still to this day

That is ONLY true in a narrow band of temperatures around the freezing point of water. From about 2-3 degrees C on upward, water expands with increasing temperature, just like everything else. From about -3C on downward, ice contracts with decreasing temperature, just like everything else.

Not quite, but they're related and the effects are almost identical.

Cavitation damage occurs anytime a void (bubble) surrounded by a liquid collapses violently, producing a pressure pulse that can damage metal.

In micro-boiling, the "bubbles" are caused by water flashing to steam and they collapse violently when they migrate into cooler water and the steam re-condesnes almost instantly. This is the "hissing" sound you hear when you heat a pan of water on the stove BEFORE it begins to boil visibly.

In a water pump, the bubbles aren't caused by true "boiling", but are actually caused by the process of cavitation (local reduction in ambient pressure to a point below the vapor pressure of the fluid) caused by the motion of the impeller blades. But when the bubbles collapse, the pressure pulses still erode metal.

"Steve" wrote

Audi

Audi

Ian

I would still think any liquid in the situation would boil if it got hot enough.

BTJustice

Thanks for the information in this and the post 5 minutes before. Good information.

BTJustice

Because of that? Don't be silly. Show me 1 mechanic that knows everything. None of them. Everyone has to learn from someone that knows more hopefully. That is where I got that information; from someone who knew more at the time. Someone just posted that the car is an Audi.

BTJustice

Am I reading this right? The Audi pumps coolant through the tranny? Learn something new everyday.

"Buford T. Justice"

That is the make that "shiden_kai" says does it.

BTJustice

Thank you! And why does that NOT surprise me that a company that should have stuck to air-cooled engines would be the one to do it that way? :-)

"Joe Poitras" wrote

It doesn't "pump" coolant through the transmission, it just has coolant pipes running back to a cooler that sits at the rear of the transmission. I know this, because my wife owned an 87 Audi 5000 and I had to do all the repair work on it.

In this case, Audi decided to run coolant back to the transmission, instead of running trans fluid up to the radiator.

Ian

Does transmission fluid really get so hot that the hot engine coolant helps keep it cool?

I'd think that there were better ways to cool a tranny!