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Intermittent coolant smell inside car (without other heater core symptoms)
99 ES300 175k
(Car has received only toyota long life red, and has coolant replaced every 25k miles since 1999, no accidents, maintained like an OCD person before and after I bought it at 133k)
A couple weeks back I did a coolant drain/fill. After I replaced the fluid with new long life red (half distilled water) and burped the cooling system, I spent the next day topping off the overflow container. I ended up getting a little bit more than over the FULL mark. So a few days later I smell coolant inside the car through the AC, but there are no other symptoms that would make me think heater core leak (no loss of coolant, no wet carpet, no steam through AC, etc). The next day I end up using a turkey baster to remove a little coolant from the overflow so that it's more about halfway between the low and full mark. The coolant smell disappeared instantly after doing that.
I don't know the insides of the cooling system all that well, so I thought maybe there was just a little too much coolant in the system and somehow that made me smell it (baffled). I think normally cars are supposed to get rid of any extra you put into it.. but mine wasn't getting rid of any. Does this model have a 100% contained cooling system? The overflow doesn't have a tube with an exit. BTW, this was my first time doing a coolant drain/fill. It was pretty easy, so I don't think I did anything wrong.. anyhow.. on to the next part of the story..
So 2 weeks later (today) I smell coolant in the car again after starting the car up (it's not super strong, but it's there) The AC wasn't even on either. There's no other symptoms of a leaking heater core, and there is no loss of coolant as viewed from the overflow container.
If anyone knows more about the intricacies of the cooling system and wants to propose a theory.. I'm all ears!
So your coolant overflow reservoir cap is sealed? (E.g., overlfow from neck in, but no exit neck and hose). because on our 2002 there is a vent path. It is simply a few inches of hose overboard and down the inner fender liner, but there is a vent.
The only totally sealed systems I’ve run across are the crap-tastic GM “death-cool” systems with the 2-eha oxidizing plasticizer in it. If you were not confident it had always been Toyota red, I would suggest a possible mixing which eats components like heater valves, radiator necks, etc. But since you rule that out and say your system is sealed, I would wonder about pressurization and it forcing some past heater core seals or elsewhere that gets inducted with cc use.
Quick reply Oro!
Mine does not have any exit "hose" but now that I took a closer look.. I do see a little open spot on the edge of the overflow cap that might technically be where extra could come out. There would have to be a lot of extra though, I would think. Pictures attached.
The system will push out any coolant that is above the maximum line in the overflow. You can keep adding coolant so it sits above the line when the engine is hot but the extra will be expelled over time. The system is not closed, the radiator cap controls when the expanding coolant is pushed into the reservoir and pulled back into the radiator when cooled.
So here's a question to anyone.
How would YOU go about this problem? I don't think it's something I can ignore, as I hate smelling coolant and it must mean something. For the time being my plan is to give it a week and see if anything changes.
When refilling, did you accidentally spill some coolant by the filler neck? You may be smelling coolant that has pooled on top of the engine which is burning off. Also confirm the coolant level by removing the radiator cap when the engine is cold. Next time you catch a whiff of coolant switch to recirculate and see if the smell dissipates.
When refilling, did you accidentally spill some coolant by the filler neck? You may be smelling coolant that has pooled on top of the engine which is burning off. Also confirm the coolant level by removing the radiator cap when the engine is cold. Next time you catch a whiff of coolant switch to recirculate and see if the smell dissipates.
HomerJay
"When refilling, did you accidentally spill some coolant by the filler neck? You may be smelling coolant that has pooled on top of the engine which is burning off"
Actually, when I was bleeding the system I used the no-spill Lisle funnel. The correct adapter didn't fit quite right and there was quite a bit of coolant spilling out from the radiator neck area from the sides of the no-spill funnel adapter. I had to use one of the other adapters and actually bend the rims of said adapter to create a tight fit on my system. Even then, while bleeding, a tiny bit was still spilling. I can't say I was very happy with that Lisle No-Spill funnel lol. There was a cleanup to do on the garage floor. I'll have to check around a bit to see if there's any pooled coolant, but It's been almost 3 weeks now.. so I think any might have fell to the floor or evaporated, but who knows.
"Next time you catch a whiff of coolant switch to recirculate and see if the smell dissipates"
I actually keep my car in recirculate mode basically 95% of the time, so it's already on that. The coolant smell was gone for the past 2 weeks or so, but just came back today.
The only thing I did different was this morning, after leaving work at 6AM, I actually turned on the front defroster option while using the heater , which turns off recirculate mode and goes into fresh air mode until I turned it back to recirculate mode a minute later. I have no idea if this has anything to do with the coolant smell possibly coming back, but I always think of everything I did when something happens with my car. (note: coolant smell didn't come back until after I started the car in the afternoon. After sleeping. I wake up around 2pm)
"Also confirm the coolant level by removing the radiator cap when the engine is cold"
Just did a check for ya. It wasn't quite cold (slightly warm). It's been sitting for 2.5 hours.
I also did a flashlight search around places and didn't see any kind of pools of coolant anywhere.
[pictures attached]
I would go to the auto parts store and get some heat rated hose, and insert it into that vent orifice. Then when it is expelled, it will be directed down the inner fender instead of belching out a little higher.
The fresh air intake is somewhere just aft of that (I think under the screen below the windshield/behind the firewall) - I say this because the filter is behind the glovebox on that side, roughly that height. Maybe you just got some fumes ducted into the cabin - it would not take very much to make a strong smell. I find my level stays closer to the lower mark and not the “Full” mark, so I I guess I shared it here because I don't know where else to. I certainly can't post that to facebook for my family to read... wouldn’t worry about filling it that full, it will probably belch it out as L2K described above. BTW, if you haven’t changed that cabin air filter in 10 years or so, do it, or at least take it out and clean it. You can be surprised at the nastiness that can accumulate in there and your cabin air is being pulled through.
I would go to the auto parts store and get some heat rated hose, and insert it into that vent orifice. Then when it is expelled, it will be directed down the inner fender instead of belching out a little higher.
The fresh air intake is somewhere just aft of that (I think under the screen below the windshield/behind the firewall) - I say this because the filter is behind the glovebox on that side, roughly that height. Maybe you just got some fumes ducted into the cabin - it would not take very much to make a strong smell. I find my level stays closer to the lower mark and not the “Full” mark, so I I guess I shared it here because I don't know where else to. I certainly can't post that to facebook for my family to read... wouldn’t worry about filling it that full, it will probably belch it out as L2K described above. BTW, if you haven’t changed that cabin air filter in 10 years or so, do it, or at least take it out and clean it. You can be surprised at the nastiness that can accumulate in there and your cabin air is being pulled through.
Thanks Oro. I think maybe there is some (perhaps even just a thin layer of dried out coolant) somewhere and perhaps turning on fresh air that morning was enough to bring some of the fumes into circulation for awhile. This morning driving home from work I didn't smell a single bit of coolant while running the heater. *Shrug* I'm keeping my nose on it haha. The good thing, it seems to me.. based on a toyota camry 97 heater core replacement video (it's at the same spot on my official 99 lexus ES300 repair diagrams).. you can manage to replace the heater core without taking the dash apart. I don't think my heater core is bad, but I'm just looking out for the future
Also, last year I replaced my cabin air filter, so I'm pretty fresh!
05-03-18, 03:31 PM
Intermittent coolant smell inside car (without other heater core symptoms)
