What's going on with my coolant?

My only concern is that there are signs of dried fluid on the outside of the tank and the tank is empty. That shouldn't happen.

I do agree that refilling it and watching it is probably prudent.

 

You're still assuming that the cooling system was full from the factory. It very well could have slowly been pulling coolant out of overflow into the system and now the overflow being empty is what created this post.

Coolant leaks on these trucks are very obvious with the pink coolant as it dries white, a quick once over of the engine bay will likely find if there is a leak. If it is an internal leak, there would be other signs, steam coming out of the exhaust, rough idle, etc.

If this is the ONLY issue, and so far that is what it seems to be, then I don't think anything major is going on.

Do you take your truck back to the dealer after an oil change because there is a single drop of oil coming off the drain plug? Or do you wipe it off and then check it after a few days to see if it stayed gone?

 

That nipple that the black rubber hose is attached to, goes down inside the reservoir tank so that it’s always submerged. If it wasn’t, it would pull in air. That’s how that works. If you dumped your whole reservoir tank out on the ground, you wouldn’t think it was a “tiny” amount.

 

If the truck was under warranty I would bring it back to be documented. To many issues with these trucks to not have stuff documented early on. Covering your ass as best as possible with new vehicles is important in my book.

If it was on an older truck I wouldn't care as much as documenting things are pointless.

 

My reservoir tank has been empty since I last changed coolant in 2018.

The radiator takes, what 2 gallons? or 1.5 I forget now. But the reservoir does not..

 

Sounds like you should have the dealer look at it

but really. The tank should never be empty.

 

Coolant expands when it gets hot this causes an increase in volume and. pressure. Put a full unopened gallon in the sun for awhile and it will expand. The fluid being pushed into the expansion tank gets pushed out the hose because it’s doesn’t have anything to stop it. The rubber hose becomes more pliable when it gets super hot as well. It doesn’t happen all the time but I’ve seen this many times before. It could be leaking from somewhere else to though. Also like the other member suggested it may not have been full from factory. How many miles are on it? How many time has the hood been opened? I would fill the tank make sure the rad is also full inspect the rest of the engine for leaks clean up the tank and check it once a week to see what’s happening. I work on cars for a living though so from his perspective it makes sense to just have the dealer handle it.

 

I got my free frame. Ill never go back to a dealer again.

OP should also check for rust

 

My 2nd gen did this a lot. Just have to top off the coolant every few years. No biggie.

As long as there no leak elsewhere it’s not worth the time bringing it to the dealer. Just add enough coolant to be in the middle and be done with it.

 

I have a ‘22 (3 months old) and it was leaking coolant but from the back of the engine.
About 2 weeks ago I took it to the dealership. They replaced some coolant bypass hose along with some other parts to fix the leak.

 

Exactly. I don’t understand how people think this is normal on a vehicle that’s less than a year old.

 

its pretty simple.

top it off, go drive it for about 30 minutes. pull into a driveway and see if its leaking from the tank or somewhere else.

Just be weary of where the AC drains.

 

Every single one of my past and current Toyota cars did this. Prius, Rav4, Tacoma, Yaris, Lexus IS250, ES350, RX330, GX460, Tacoma. I've even had it happen on a few Subarus with this type of overflow tank design. I never had overheating issues. My belief is that the hot coolant evaporates and leaves all of the additives right at the top of the tank. This explains why you never see it actively leaking or dripping coolant. If it was an active leak it would still be wet.

 

no popcorn emojis yet?

 

Sorry, but you do NOT understand how this system (which has been in use for a long time) works. When the system cools, the coolant is pulled back into the radiator. And when the overflow tank gets low (which normally it shouldn't ) you top off the system by using the overflow tank.

 

Then you have no idea as to how to maintain a vehicle. Why are you giving advice?

 

Some of you must have skipped coolant system day in highschool auto tech.

Radiator cap 101 - When the coolant gets hot, thermally expands, and the cap pressure set point is reached the excess coolant flows into the tank. When the coolant cools, thermally shrinks, and the coolant system reaches vacuum the fluid is drawn back from the tank. The cap is usually the high point so any trapped air is pushed out through the tank during heat up, replaced with coolant from the tank during cool down.

If the cap didn't allow coolant to return as it cools and shrinks, the hoses would collapse (technically crushed by atmospheric pressure). Collapsed hoses is one of the obvious signs of a bad radiator cap.

Edit: And if you're confused by the hose on the top of the tank, it's connected to a "straw" to the bottom of the tank so it should always be submerged in fluid. The air vent is in the tank cap, pointed downward for safety in case of a boil over.

 

I don't get it either. People love to normalize issues with these trucks and just turn their head the other way.

 

I definitely think it’s normal to have SOME evaporation, but an empty reservoir with less than a year old? Probably not normal.

 

You might want to inspect the connector on the back of the engine that connects the left and right banks together. It's a two piece unit made of plastic. It can split causing the engine to leak coolant. I've heard you can check it by crawling under the truck and inspecting the right side of the transmission housing for engine coolant running down the side. Should be a dried trail of it when cold. There's another thread on tw that talks about it. I'm just too lazy to find/link it.