Yaris Hybrid 2021 — gas fume smell outside after short power on time?

[baxuz]

Today I had to move the car 4 times by a few meters, and I noticed that after I turn off the car (30s power on time, 2m driving) there was a really intense gas fume smell. I actually thought that the construction workers nearby were using some solvents the first time.

I've had the car for almost a month now and I haven't experienced anything similar so far. Even the weather was nice, 7°C, so not a cold start or anything.

I used to do this car moving dance due to how narrow my street is all the time with my old 2001 Hyundai Atos and I've never experienced this, nor did I notice the Yaris smell like this before. What could cause it, and is it something to worry about?

[Cyker]

Is it just petrol fumes? Is fairly normal if so - Had similar in all my non-hybrid petrol cars if I just fired them up for a few seconds to move them. Lots of unburnt petrol in the exhaust. This is partly why ICE efficiency is so awful when the engine is cold!

It's one reason the Mk4's reluctance to go into EV mode, ever, is a bit annoying, as if I could move it without the engine starting up for such things that would be ideal, but it always fires the engine up when I turn it on!

[TonyHSD]

If you have to move the car like you had described best way to do is to switch immediately to ev mode after you have started the ignition and switch off heating fan, the car will remain silent, no engine will be running and no nasty smell of fuel. If you start the car normally as you are saying for only 30 seconds and then switch off while engine was running you are doing it wrong and it is not recommended., best  to wait for the engine to turn off itself and then you can switch off ignition and leave the car. Engine is always cold when the car was not in use for some time no matter if temperature outside is low or high and if you cut it off while running you are actually flooding it with petrol 👍

[TonyHSD]

2 minutes ago, Cyker said:

Is it just petrol fumes? Is fairly normal if so - Had similar in all my non-hybrid petrol cars if I just fired them up for a few seconds to move them. Lots of unburnt petrol in the exhaust. This is partly why ICE efficiency is so awful when the engine is cold!

It's one reason the Mk4's reluctance to go into EV mode, ever, is a bit annoying, as if I could move it without the engine starting up for such things that would be ideal, but it always fires the engine up when I turn it on!

You need to turn off hvac fan immediately after starting the car and if you have 30% or more Battery power the engine will not start. I do this few times a week with no problems. 👍

[baxuz]

Thanks for the replies.

The car was in eco mode and the HVAC was turned off immediately. The Battery was almost half full too.

It's weird that an old bucket like the Atos didn't have the smell.

[Cyker]

36 minutes ago, TonyHSD said:

You need to turn off hvac fan immediately after starting the car and if you have 30% or more battery power the engine will not start. I do this few times a week with no problems. 👍

Yea that's one of the biggest differences in behaviour between your Auris and the Mk4 - Since it's been getting colder I always turn the HVAC off before I turn the car off, so that when I turn the car on the next day it's already off. Even with that and a 50% charge, I have *never* gotten the EV mode to work right after turning the car on; It always says something like EV Mode unavailable, and then starts the engine up a few seconds later!

So far I think I've gotten EV mode to work once, and it was after climbing a long hill really slowly in traffic so the car had charged the Battery up to 7 bars when I got to the top! Other than that it's always some variation of not enough charge, going too fast or just generically unavailable  

I guess that 0.7kW Battery just isn't good for it; They honestly should have just omitted the EV button from this car and saved a few pennies!  

 

Some cars do get it worse than others; I think it's something to do with how aggressive the automatic 'choke' is in trying to warm the engine up (Yes yes you pedants injection engines don't have an actual choke but you know what I mean!!), and also the size of the cylinders (The Mk4 has very large cylinders considering it's only 1.5L because it only has 3 of them - They're the same size as you'd get from a 4-cylinder 2.0L engine!)

 

[TonyHSD]

16 minutes ago, Cyker said:

Yea that's one of the biggest differences in behaviour between your Auris and the Mk4 - Since it's been getting colder I always turn the HVAC off before I turn the car off, so that when I turn the car on the next day it's already off. Even with that and a 50% charge, I have *never* gotten the EV mode to work right after turning the car on; It always says something like EV Mode unavailable, and then starts the engine up a few seconds later!

So far I think I've gotten EV mode to work once, and it was after climbing a long hill really slowly in traffic so the car had charged the battery up to 7 bars when I got to the top! Other than that it's always some variation of not enough charge, going too fast or just generically unavailable  

I guess that 0.7kW battery just isn't good for it; They honestly should have just omitted the EV button from this car and saved a few pennies!  

 

Some cars do get it worse than others; I think it's something to do with how aggressive the automatic 'choke' is in trying to warm the engine up (Yes yes you pedants injection engines don't have an actual choke but you know what I mean!!), and also the size of the cylinders (The Mk4 has very large cylinders considering it's only 1.5L because it only has 3 of them - They're the same size as you'd get from a 4-cylinder 2.0L engine!)

 

Very likely to be because of the Battery state of charge, my one is always full when I am at home and let me keep the car in ev mode for minutes, or I can even drive around the block a bit. , sometimes I do exactly that to top up the tyres with air compressor connected to the 12v socket, car is in ready mode with heating fan off ev button pressed and all quiet for good amount of time. I had tricked the car before not to start its ice with switch on ignition then select N and let the car roll backwards in neutral, the engine didn’t start, when I stopped I turned off ignition first and the car automatically selected P, hand brake on and all good. 👍 

[TonyHSD]

44 minutes ago, baxuz said:

Thanks for the replies.

The car was in eco mode and the HVAC was turned off immediately. The battery was almost half full too.

It's weird that an old bucket like the Atos didn't have the smell.

Have you turned off your engine while was running? If yes that can be the reason. Perhaps next time wait for the ice to run it’s cycles and switch off itself then turn off ignition and charge if it’s smells the same. 👍

[baxuz]

22 minutes ago, TonyHSD said:

Have you turned off your engine while was running? If yes that can be the reason. Perhaps next time wait for the ice to run it’s cycles and switch off itself then turn off ignition and charge if it’s smells the same. 👍

Yeah. It was running. That must've been the only difference now that I think of it.

[trashman1965]

Later cars don't behave as the older ones did. I always used to put my auris in ev when taking out of the garage and drive first couple hundred yards on electric. Could do that any time of the year unless hv Battery was low.

Only managed it once in the corolla and that was when it was warm....same message always  "ev mode unavailable" as opposed to hv Battery low. Same with 6/8 bars on hv Battery.

Also my corolla did exact same with strong fuel smell on first start, same here not particularly cold. It might be if it starts in direct injection mode instead of port (which it seemed to) and last journey engine was definitely off when parking up.

[preperationlaunch]

1 hour ago, Cyker said:

Yea that's one of the biggest differences in behaviour between your Auris and the Mk4 - Since it's been getting colder I always turn the HVAC off before I turn the car off, so that when I turn the car on the next day it's already off. Even with that and a 50% charge, I have *never* gotten the EV mode to work right after turning the car on; It always says something like EV Mode unavailable, and then starts the engine up a few seconds later!

So far I think I've gotten EV mode to work once, and it was after climbing a long hill really slowly in traffic so the car had charged the battery up to 7 bars when I got to the top! Other than that it's always some variation of not enough charge, going too fast or just generically unavailable  

I guess that 0.7kW battery just isn't good for it; They honestly should have just omitted the EV button from this car and saved a few pennies!  

 

Some cars do get it worse than others; I think it's something to do with how aggressive the automatic 'choke' is in trying to warm the engine up (Yes yes you pedants injection engines don't have an actual choke but you know what I mean!!), and also the size of the cylinders (The Mk4 has very large cylinders considering it's only 1.5L because it only has 3 of them - They're the same size as you'd get from a 4-cylinder 2.0L engine!)

 

That's weird, the 3rd gen Yaris will generally keep the charge at a stage where you can use EV mode. I'd have expected the Mk4 which has a Battery that is a lot more capable of charge/discharge would be happier about it.

It'll engage above 50% Battery on mine, provided the car hasn't started a warm up cycle, if it has, it won't let you force EV mode til it's warmed up enough.

The automatic 'choke' on the hybrids is quite cool too, not sure if the mk4 is the same, but you hear a distinct engine note change after about 30-60 seconds on earlier ones. Before that, the car is running mostly on the electric motors, it's running with very late timing to heat the catalytic converters up quicker. There's all sorts of witchcraft involved in the 4 or 5 warm up stages the Hybrid system goes through though.

[Cyker]

It does sound like the earlier hybrids put more charge into the Battery - Mine is almost fanatical at trying to keep it as near to 50% as possible - It's very very difficult to get it above that unless I'm accelerating along an A-road or motorway up a hill or some situation that is demanding too much torque for the electric motor to run (As soon as I stop accelerating, even at 60-70mph, the car will immediately cut the engine and switch to electrics until it drops below 50% then the ICE fires up again!)

It does seem like EV mode is only allowed at 5-6 bars, but the car never leaves the Battery at that level for long enough for the EV mode to be useful...

Still, this obsession with keeping it at 50% SoC should keep the Battery healthy for far longer than any EV could possibly achieve - I think I'd be much happier buying a 10 year old one of these than a 10 year old EV!

 

 

[baxuz]

What still bugs me is how a 20-year old Atos didn't suffer from unburnt gas in the exhaust in these conditions.

I'll try seeing if letting the car shut down the engine on its own fixes the issue.

Which then begs the question: what's different, combustion-wise, between letting the car turn off the engine on its own and me cutting it off with the power button?

[MikeSh]

35 minutes ago, baxuz said:

Which then begs the question: what's different, combustion-wise, between letting the car turn off the engine on its own and me cutting it off with the power button?

Probably just that it will only turn it off when it has achieved a time, temperature, mixture level that doesn't leave unburned fuel in the exhaust pipe.

When you stop it it may still be in a rich mode.

[TonyHSD]

2 hours ago, MikeSh said:

Probably just that it will only turn it off when it has achieved a time, temperature, mixture level that doesn't leave unburned fuel in the exhaust pipe.

When you stop it it may still be in a rich mode.

That’s the one!👌

Some other cars even can choke themselves and refuse to start for hours afterwards. My Neighbor does that to her car non hybrid and she always calls RAC to come and help, one day I talked to the mechanic he was working on her car what is all about and he said to me too much fuel in, engine is flooded. I seen her doing exactly that, start the car, move it 2 meters and turning it off, I explained to her the issues she has, made her understand the matter and she never had any problems since.
When you start any ice car on cold wait until revs dropped down themselves ( hybrids engine off) then turn off ignition. Rules ✅🏁👍