Antifreeze smell when hot, using a bit of coolant

So, my 2021 has always had an antifreeze smell coming from the engine when I park in the garage. I've had it looked at, nobody can find a leak, but it is using coolant. Filled the overflow bottle to the fill line 3,000 miles ago, and now it's down an inch.

To me, this doesn't seem normal. Is it? Even my Wrangler didn't use coolant and never smelled of coolant after being driven.

 

Not normal. When was the last time you changed your oil?

 

First of all, I've noticed the coolant smell when hot since I first bought it, and have brought it back numerous times to have it checked.

I changed the oil at 1,000 miles, then 6,000 miles, and then I'll use the dealer for my free 10k oil change.

 

I hope you don’t think I was being flippant when I asked. Coolant in the oil is a sign of a bad head gasket, which would be the worst-case cause of coolant loss. All the other causes are merely a nuisance.

Speaking totally off the top of my head now, if you turn on the heat and don’t smell it in the car, that would tend to strike the heating system off the list. Maybe have a look at the radiator cap. Look for stains around the cap.

 

Doesn’t sound good. I would definitely get Toyota to make it right before warranty expires.

There are test kits that take a sample of your antifreeze and can tell if the head gasket(s) are leaking. I saw it on a Scotty video.

 

Maybe it’s leaking only at hot temperatures, small enough to not see it ? Maybe a hose clamp down at the bottom ?
You’d see smoke in the morning, IMHO.

 

I have read on other threads that the radiator caps are not very reliable. It would be cheap to replace and see what happens.

As @Slopemaster said, there is a dye that can be dropped in the radiator with the cap off and it will react - change color - if there are exhaust gases in the coolant. Hope that is not what you have.

 

Oh yeah, no, I didn't mean to sound annoyed. Sorry. Totally agree, and meant to add that in my post about oil changes. We didn't see the usual signs of coolant in the oil, but, I haven't tested it either so, that might be a next step.

I appreciate everyone's responses here. Definitely helps.

 

I'll try the coolant test next. This is the hard part about diagnosing things like this. The engine needs to be fully warmed up to experience the coolant smell. I generally notice it if I've put about 20 miles on it. Not something the average dealer test drive will accommodate! Trying to do what I can to gather data so when I ask Toyota to fix it, I can give them something meaningful to look at.

 

My 2021 does exactly the same thing, but does not use any coolant. It only is noticeable after a long drive like yours. I've looked everywhere and can't find any leaks but it is hard to see the back of the engine. I change my own oil and nothing there coolant wise.
I had a 2019 V-6 Tacoma that did this then I noticed coolant stains on the airbox....turns out it was a hair line crack(in the seam) in the plastic side of the radiator just below the cap.

 

Oh man, glad I'm not the only one! Thanks that's a useful tip. I have a mechanic here in my town that is the unofficial landcruiser guy, super nice and he inspected it for leaks. As you said, it can be hard to find, since it's using it slowly. I'll also check the radiator really closely.

Going to get a block tester to check the coolant for exhaust gases.

 

This brings up another thought. When the truck is cold, open the radiator cap, and put a bit of dye that responds to UV (black) light. I don't recall if coolants already have UV dye in them, some engine oils do. Anyway, put the radiator cap back on and drive you round trip commute. In the dark, a UV black light in your engine compartment would light up the source of any leakage.

 

Yes! I was actually just doing a search on this. There is dye that can be used. I'll probably try that as well.

 

Let me know which dye and where you get it as I might give this a try.

Another thought I had since it is only when it's been run a while is maybe coolant has flowed in/out of the overflow tank or whatever it's called, which then you can smell as it does have a what looks like a vent in the cap. I really only notice mine when I park in the garage right after a long drive.

 

That was my thought too. I'm going to check it all, and if I'm wrong, cool. If I'm right, I'd rather know now while it's still under warranty.

 

I have had the same thing happen on several occasions - a slight coolant smell after driving it for 20 min or more and parking in my garage or walking around the front end. No perceptible coolant loss at the expansion tank. I haven't done a thorough check of the coolant lines but I did notice some coolant residue around the expansion tank cap and a little on the hood liner. I cleaned that off and then reseat the cap.

Seems better but still need to look at the lines.

 

YOU HAVE TO INSPECT THE RADIATOR CAP! looks like the CCP part in todays world ...

 

Have you found out the cause of the smell? Just picked up a 2021 SR5P about a month ago and have noticed an antifreeze smell after a 20 min drive, too. It seems to be smoking a bit, too. When peeking under the hood I don't notice any leaks but my radiator hose is white. I read on a few forums it is just residue but could that be the culprit?

 

Agreed its not normal. My 1GR powered Tacoma was a couple inches low on the overflow after 8 years of driving - that can happen from evaporation over such a long time time. Using the same between oil changes shouldn't happen.

Do you smell it from outside, or do you smell it in the cabin when driving?

Smelling it inside when the heat is on could indicate a slow leak on one of the heater core fittings. If its slow enough the leaking fluid may just evaporate over time and you wouldn't notice any puddles/stains....

 

I only smell it when I'm outside of it. I had a local Toyota dealership take a once over when I first bought it (since I didn't buy it from a TD in the first place) but they found nothing wrong with it. Shortly after that I noticed the antifreeze smell. Might just need to take it back but make sure I drove it for 20 mins+ before they take a look at it...

 

My 2010 Tacoma always smelled like coolant whenever I'd go through a river crossing. There was always crusty coolant at the overflow hose inlet.

 

If you haven’t yet, Check around the water pump.

 

Sounds like a heater core issue to me. I’ve had plenty of heater core failures with every Ford I previously owned.

Check the A/C condensation drain tube for evidence of antifreeze. Not sure how Toyota does it, but the heater core and evaporator typically are housed in the same box under the dash.

 

well the radiator cap is around 2020-21 yr change the radiator cap ...many have those caps 2021yr

 

Yep, I had a tiny crack in the radiator. Repaired under warranty. Took many many many many many many many many many visits to the dealer until one mechanic and the head of the service department went through the system with a fine toothed comb, while I waited and watched by video (wouldn't let me in the service bay and I told them I wasn't leaving until I saw them do the work) and found it. Involved removing body work, etc. They hated me, and thought I was being overly sensitive for such a minor problem.

I'm like, seriously? Let me know how minor it is when it finally breaks and you're 100 miles from pavement and no functioning coolant system.

Their service head responds with, well, these are really just used for dirt roads around here, nobody takes them on hardcore off-road trails.

WTAF.

 

Good on you for fighting this and getting a resolution. The dealers response is total and absolute BS, and I am sure you will never use them again. Its simply not acceptable for a brand new car still under warranty to have a flaw like this, doubly so for a brand like Toyota whose entire reputation is built on their legendary build quality.

I don't care where you use it - Whether its in the mountains or on the freeway, that radiator blowing would leave you stranded at best; and might result in something nasty like a cracked block if you didn't catch it before it massively overheated. Completely unacceptable and I would have been complaining to Toyota corporate if they kept stonewalling.

Congrats on getting to a resolution.

 

My radiator cracked on my 97’ Tacoma, but it took 20 years and 200k miles to happen. Unbelievable that you had a radiator failure on a brand new truck. Must have been a fluke. Glad you were able to get it fixed.