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Do not put green coolant in this car, its a glycol mix which will mix with the proper oem stuff and become gel and destroy your entire cooling system. Either way, toyota red coolant is CHEAP and easy to find. And that fluid looks properly dark, please change it.
On top of all of that, the coolant fill on these cars is a bolt on top of the thermostat housing. Putting coolant into the expansion tank will do absolutely nothing for the coolant system, it will not flow in your engine and radiator, it will simply get pushed out of the expansion tank and out onto the grounf. Hop on lexls.com and view the tutorial for changing coolant and how to properly bleed the system of air bubbles.
There's a lot of misinformation in this one post. Yes, green coolant is a glycol mix, which happens to be what Toyota says you should be using. Toyota red is a glycol mix dyed red. Green is fine as long as you change it as the recommended intervals. And of course, coolant in the expansion tank absolutely will be used in the coolant system if needed. Try changing your thermostat. You will lose some coolant. That lost coolant will be replenished from the expansion tank.
In general, it seems some authors in this thread are confused about how the coolant overflow tank works in these LS400 engines vs. for other manufacturers. The basic concepts and underlying physics are the same, but there is an important difference based on whether the "radiator cap" is on the radiator vs. the expansion tank.
For other cars, they may have the radiator cap (with a release valve and a vacuum valve) to release coolant into an expansion tank when hot, and then suck it back into the engine/radiator cooling system when cold. When cold, the coolant contracts, pressure drops within the radiator, and the vacuum valve in the radiator cap will open to allow coolant to be sucked back in to fill the radiator. Yes, no air should be in the radiator for those systems. If there is air, and it is not bled, it will hopefully find its way to the top of the radiator, where it will be pushed out to the expansion tank when the release pressure is exceeded (which is normal in those systems).
In that case, the expansion tank is not pressurized. It is at atmospheric pressure and you can actually lose a small amount of coolant over time due to evaporation. In this design, having the radiator cap's release valve open to vent to the expansion tank is common, followed by sucking it back in after a cool down. A small hole in the expansion tank allows equalization with atmospheric pressure at all times, while not allowing a fluid leak.
In our cooling systems, the "radiator cap" is not on the radiator. It is on the expansion tank. And unlike that other type of system, our expansion tank cap is only supposed to exhaust when something is wrong, not on a regular basis. And there is no sucking back in, because it is air on the other side.
At ALL TIMES, static pressure is equalized between the engine, radiator, and expansion tank. If pressure in one place were higher, coolant would flow there to equalize. No valves in between, just hoses. So when the engine is hot, but not hot enough to exceed the (~13 psi?) release pressure of the cap, that pressure will exist equally in the engine, radiator, and expansion tank (including air / coolant vapor, and coolant). The dynamic pressure due to flow driven by the water pump will superimpose upon this, but that is not a major factor.
As temperature increases, so does the volume of the coolant. First thing it does when expanding is to compress the air gap. That results in a pressure increase, which also increases the boiling point of the coolant, extending the range/capacity of the cooling system. Generally, things are sized so that at the max operating temp when nothing has failed or is abnormal, if level is set properly, the air gap will accept the full expansion with no overflow. If expansion exceeds that or boiling occurs, the excess coolant/air/vapor will leave through the radiator cap, exhausting through the black hose onto the ground, never to be seen again.
And BTW, yes, for those other (not Lexus LS400) cooling systems, with a radiator cap on the radiator, and an expansion tank at atmospheric pressure, filling coolant into the expansion tank will only help to the extent that a little is sucked in through the vacuum valve after each drive. You cannot fill those systems through the expansion tank after emptying them. You must remove the radiator cap and fill there.
Do not put green coolant in this car, its a glycol mix which will mix with the proper oem stuff and become gel and destroy your entire cooling system. Either way, toyota red coolant is CHEAP and easy to find. And that fluid looks properly dark, please change it.
On top of all of that, the coolant fill on these cars is a bolt on top of the thermostat housing. Putting coolant into the expansion tank will do absolutely nothing for the coolant system, it will not flow in your engine and radiator, it will simply get pushed out of the expansion tank and out onto the grounf. Hop on lexls.com and view the tutorial for changing coolant and how to properly bleed the system of air bubbles.
My manual says to only use glycol type of coolant.
My manual says to only use glycol type of coolant.
Yes, and when describing the coolant-water mix ratio, it refers to it more specifically as ethylene glycol (propylene glycol is the other major type of glycol used in antifreeze).
The green stuff is ethylene glycol.
Here are some links on coolant in general, one from Toyota.
https://parts.olathetoyota.com/blog/...nt-color-guide
quote from that one: "Here’s a fun fact: antifreeze starts out colorless. All the green, orange, red, pink, amber, and blue coolants you see on the shelves are dyed." The color is an added identifier. It does not necessarily indicate a fundamentally different chemical.
In my opinion, the Toyota one, and partly even the other one are not as forthcoming about the real reasons for the zillion types. They emphasize the need for engine corrosion protection, but from my reading and experience I'm more convinced that the reason is much more strongly driven by environmental concerns, particularly for European manufacturers. I of course do care about the environment, probably more than most people, but my conclusion is that all of the above will be fine in just about any engine, as long as you're careful about a chemical reaction from mixing different coolants. So when I figured this out a long time ago, I standardized on some coolant that was cheap and easy to get so I could conveniently maintain all my cars with it.
My '91 was built when West Germany was still a thing, so I don't think all the advances in coolant options since then are required to keep my engines from rusting out. They probably do make it safer for the environment, and for animals drinking it (several years ago, it became standard to put something in there that makes coolant taste bad, to protect animals from wanting to drink it due to its naturally sweet flavor). And of course, any coolant currently manufactured has to meet environmental regulations. But I don't lose any sleep about the coolant damaging my engine - in general. Still, each time I get a new car, I double check to be sure not to make a mistake.
Well damn, I couldn't tell what color my coolant was, I was just checking through the front of the panel but it is red. My reservoir was low I added a small amount of the Green to top it off. My reservoir does not seem to move weather hot or cold. I will change it and do a flush. Would the gel issue happen right away? I have been driving it a bit since then and have not noticed any difference in engine temp. I have noticed my hood gets pretty hot but its always done that.
I would not worry so much about just a little of the green. But pretty soon, I would go ahead and flush it carefully, running pure water through there to get everything out. Then take your pick and refill with whichever one you like, and stick with it.
That's partly why I always advise to top up with water when just a little is needed. The potential danger (none) from going down to a 49-51 coolant-water mix ratio is less than the chances of getting an unexpected chemical reaction between mismatched coolants.
And I don't know if the formula for Toyota Red has changed over the years. I expect it has, since everything else has changed. And when you get a new (old) car, you may not know what is in there, for any of the fluids.
07-17-19, 05:38 PM
