Thanks for the info.
Added another comment to my original after you replied. Would like to see if someone else here knows more about this system and can shed some more light.Sponsored
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Is your Tacoma consuming coolant?
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Added another comment to my original after you replied. Would like to see if someone else here knows more about this system and can shed some more light.
This I’m not sure about either, though it does seem plausible on the odor part. I found a photo of someone’s degas tank from Google and took a closer look. Same design as my Frontier had - the “radiator cap” is pressurized and anything it lets past it would go right out the little hose nipple. In this case that is the black breather cap just under the pressure cap.
So maybe the odor is “normal.” As for the level becoming low, I don’t think it ever actually vents coolant itself, so I would assume the level going low over time is either a pinhole leak somewhere or the engine using a bit of it in time.
That's a great shot - illustrates it perfectly. Thanks again. Hope it's all normal and not the start of something....This I’m not sure about either, though it does seem plausible on the odor part. I found a photo of someone’s degas tank from Google and took a closer look. Same design as my Frontier had - the “radiator cap” is pressurized and anything it lets past it would go right out the little hose nipple. In this case that is the black breather cap just under the pressure cap.
So maybe the odor is “normal.” As for the level becoming low, I don’t think it ever actually vents coolant itself, so I would assume the level going low over time is either a pinhole leak somewhere or the engine using a bit of it in time.
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@BLtheP that's good to know, but on the other hand to say it's been like this for a long time I don't think is the case. My 2016 5th gen 4Runner and several Lexus' (2013 and 2014) in my driveway both have the open to atmosphere vented expansion tank. I'm confident on that as I've topped them off after coolant flush burping.
However, you're right in that I'm looking at my 25 Tacoma right now since you had me curious, and it's designed the same way as my older cars but now they've just moved the pressure valve into the expansion tank cap so everything is pressurized normally. There's a rubber cover just under the tank fill cap with a slot on the bottom presumably for any overpressure release when the air or coolant might go past it, so it's no longer vented to atmosphere. I'd be curious to know if anyone is seeing any residual coolant coming from the plastic cap or tank areas or if it's just an air burping situation where some residual air was trapped from the factory in the system.
However, you're right in that I'm looking at my 25 Tacoma right now since you had me curious, and it's designed the same way as my older cars but now they've just moved the pressure valve into the expansion tank cap so everything is pressurized normally. There's a rubber cover just under the tank fill cap with a slot on the bottom presumably for any overpressure release when the air or coolant might go past it, so it's no longer vented to atmosphere. I'd be curious to know if anyone is seeing any residual coolant coming from the plastic cap or tank areas or if it's just an air burping situation where some residual air was trapped from the factory in the system.
I am coming up on my first coolant change interval, and I want to do it myself. I am worried that it will be a PITA to do with this new coolant system. I read somewhere that you need a bidirectional scan tool just to change the coolant properly! I really hope that isn't true and these trucks are as simple to maintain as previous years. Why should I have to plug in a computer to change a basic fluid???
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I have no apparent coolant consumption, and I wouldn't assume it's a non-issue if I were; it's going somewhere, and it could form an air bubble and then a hot spot in the cooling system.
The service guide I posted lists the procedure to pressure test the system. If you lose pressure, you have a leak to chase down. I'd have a shop or probably for less than shop labor, buy a kit and test it yourself.
It's certainly something I'd chase down while in warranty.
The service guide I posted lists the procedure to pressure test the system. If you lose pressure, you have a leak to chase down. I'd have a shop or probably for less than shop labor, buy a kit and test it yourself.
It's certainly something I'd chase down while in warranty.
These types of cooling systems have been around a while, but NOT on Tacomas, Tundras or 4Runners and I'm not sure about other Toyotas. I was only saying that this newer design principle has been around a while, and used Nissan as an example since the Frontier has used a similar design since 2005.
Basically the whole point of the degas bottle is to ensure that no air is ever in the system and if any air is introduced, the coolant carries it right back to the degas bottle to remove it. the degas bottle acts sort of like an air/water separator. All coolant eventually gets pushed to the top of the degas bottle, where the air rises and the air-free coolant goes down to the bottom of the tank and back into the rest of the cooling system, air-free.
As for venting...the old school cooling systems somewhat normally reached the radiator cap pressure and pushed coolant past the cap as needed into the expansion tank. Now the "expansion tank" is part of the system and so coolant can expand in place with room to grow. It's a lot less often that the pressurized cap (now installed on the degas tank) reaches it's pressure rating. If it does, then yes, it vents there. But it's less often now that that should ever happen.
According to the FSM, you need to at least put the water control valve into "injection mode." I'm not sure if that can be done with some scan tools or if it requires GTS+.
I am looking to buy a XTOOL D7S for this exact purpose. It seems like all the reviews on it show that it has the capability to actuate the "Electric Pump", but I would imagine the special functions on the scan tool are different depending on the make and model. If anyone with an XTOOL scanner knows if it has the capability to actuate the water control valve to injection mode, that information would be greatly appreciated.
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