Smoke smell question. Is this normal?

[Ilovemyyaris]

Okay hi everyone. I've got a 2011 yaris with less than 20,000 miles and I've noticed recently on the highway if I go more than about 80 mph I notice a smoke smell.

It happened first when I passed someone on a road. I thought maybe it was the other car, but then it happened again and now any time the engine is rev-ing a lot.

I took it to the dealer and told them about it when I got my oil changed but they didn't seem to concerned. They said they looked at it and they didn't see anything wrong.
It drives perfectly normal for the most part I think. I don't notice anything much out of the ordinary.

I never notice seeing any smoke, just smelling it through the air vents when the air or fan is on. I always have it set to circulate, I never have it set to outside air.

Only other weird smell I've noticed is that sometimes it smells moldy but I heard that was normal it's just mildew from the water from the air conditioner.

But this smoke smell has me worried. I have a theory that maybe it's just at high rpm the engine gets a little hot and the mold or whatever burns or something but I wouldn't think that to be the case.

I guess while I'm at it I might as well tell about the small thing when driving.
Sometimes if I'm going fast, but have to slow down really fast and then take off again there seems to be hesitation for about 1 or 2 seconds then a sudden jolt off. Not sure if that's normal or not. This is the first car I've actually owned so Idk if I'm just being paranoid or not.

[CTScott]

The heater core always gets fed hot water, so if you run on circulate all the time you will probably get some effect from the core since there is just a plastic flap that isolates it from the rest of the airbox when the temp knob is on full cold.

The mold is likely forming because of always running on circulate as well. It really is a good idea to run on fresh air as much as possible. Also, if your car doesn't have a cabin air filter in the slot behind the glove box, then when you have run on fresh air, stuff (pollen, debris, etc.) gets right into the airbox, where it mixes with the moisture in there to form a nasty substance that leads to more mold and will eventually plug the condensate drain.

[xnamerxx]

Originally Posted by Ilovemyyaris

Okay hi everyone. I've got a 2011 yaris with less than 20,000 miles and I've noticed recently on the highway if I go more than about 80 mph I notice a smoke smell.


I guess while I'm at it I might as well tell about the small thing when driving.
Sometimes if I'm going fast, but have to slow down really fast and then take off again there seems to be hesitation for about 1 or 2 seconds then a sudden jolt off. Not sure if that's normal or not. This is the first car I've actually owned so Idk if I'm just being paranoid or not.

Yaris's do that when you start to activate the high rpm functions of VVT-i, it has to do with how VVTI fuctions in the car under load. Mines done it since brand new and I've got almost 100k on the clock and I race the car.

I'm also guessing you have an automatic which again that behavior is normal. When you brake or let off the gas the torque converter disengages and lets the motor freewheel but when you press the gas the converter grabs again which causes that jolt all automatic transmissions do that at least from my experience.

No need to worry both of what your seeing happen is normal.

[Ilovemyyaris]

Thanks for answering. Although I'm still not sure if I fully understand what is creating the smoke smell. Is something burning on the heater core?

I'm guessing none of this is anything major to worry about?

I'll see about getting a cabin air filter too.

I'm also guessing the occasional jerky acceleration after hesitation from slowing down then accelerating is also nothing to worry about either?

[Ilovemyyaris]

Originally Posted by xnamerxx

Yaris's do that when you start to activate the high rpm functions of VVT-i, it has to do with how VVTI fuctions in the car under load. Mines done it since brand new and I've got almost 100k on the clock and I race the car.

I'm also guessing you have an automatic which again that behavior is normal. When you brake or let off the gas the torque converter disengages and lets the motor freewheel but when you press the gas the converter grabs again which causes that jolt all automatic transmissions do that at least from my experience.

No need to worry both of what your seeing happen is normal.

Okay thank you. :)

[xnamerxx]

Originally Posted by Ilovemyyaris

Thanks for answering. Although I'm still not sure if I fully understand what is creating the smoke smell. Is something burning on the heater core?

I'm guessing none of this is anything major to worry about?

I'll see about getting a cabin air filter too.

I'm also guessing the occasional jerky acceleration after hesitation from slowing down then accelerating is also nothing to worry about either?

Nothing is burning, the smell is created by oil being pumped into the cam phaser and oil vapor escaping the engine due to the extra oil being pumped to the cam covers.

Yep the jerkiness is completely normal, I'm also guessing it happens when the car is traveling 7-15mph when slowing down and you can accelerate again. Whats happening like I said before the torque converter is unloaded and freewheeling but the transmission is still shifting into whatever gear it thinks is going to be used next so when you hit the gas after doing this the torque converter loads up and since there is an abundance of torque from being in 1st gear and having a loaded torque converter you get that jerk. Like I said every automatic I've ever driven has done it. Its inherent to the design.

Both of what your experiencing are completely normal and nothing to be alarmed about. If you start smelling smoke when your not revving the engine up or idling then I'd be concerned.

As for your mold smell that's a tricky one but it likely mildew that's developed on the ac heat exchanger. I'm betting you live in a warmer place with a high humidity index. so whats happening is when you run the ac there is a heat exchanger that gets very cold and as you know from kindergarten cold things develop condensation and what happens is this heat exchanger stays cold with moisture on it allowing it to develop mildew. Get the interior cabin filter it'll help.

[pennyracer]

the car runs full fuel when the pedal is to the floor a toyota engineer drove my car and told me when you stomp the pedal the car gives full fuel to motor for max power he called that going out of closed loop meaning the ecu is not controlling the fuel delivery at that time . i have had the same problem on my 08 hb from day one even had the cat replaced by toyota that smell is your cat working very hard to clean the exhast gasses going past it and thats what making your car smell like it does that will in no way cause you any trouble down the road i have 95000 miles on it and still get that smell but not as harsh now also the toyota rep said running premium fuel is a waste of money just buy shell ,mobile, my fav chevron and dump one bottle once a year of techroline in it and you will have no problems with the fuel system at all he also mentioned toyoata builds there cars to run on regular fuel not premium though i still run the good stuff almost all the time and you do see a slight bit of better millage but the extra cost evens out with just buying regular . and do listion to ctscott he knows his stuff and is big plus to this web site