Lots of white smoke on start up

[maderd]

Hey all,
Trying to pin point an issue with my 2013 mazda 3 6 speed sky Activ

There is lots of sweet smelling white smoke out of the tailpipe whenever the car gets started. Even when the car is driven for an hour on the highway, on idle, you can still see small amounts of white smoke. Add the the coolant was ever so sightly below the min mark but doesn't drop
I had it to Mazda, and they said there is no coolant getting into the engine. They did a few tests.
Anyone know offhand what might be causing this? There is too much smoke for it just to be condensation.
I have a video, but no idea how to post it.
Thanks
Dave

[maderd]

Here is the link to the YouTube clip
https://youtu.be/TIkVkwCvAhQ

[Milan96]

Is the smoke only that bad when starting up with a cold engine? Also does it smoke at operating temperature in the summer? My 2012 sky has quite a lot of white smoke on a cold start up that I've noticed in the fall (I haven't had it for a winter yet) and will have a bit of smoke when the engine is hot (again, only when it's chilly outside). If yours does this in conditions similar to mine, then I would say not to worry. Water is a by product of combustion so it's never really worries me when I see white exhaust in cold months, and it seems like the skyactiv engines produce a bit more white smoke than other cars... Just my 2 cents

[maderd]

Hey man
Thanks for the reply.
I've had the car less than 3 weeks and this happened within the first week. I didn't notice it(or it didn't happen) for the first few days, but I did notice some white smoke a in the rest view after an hour run on the highway... And that got me looking into it.
I've never seen a car produce what is in my video and be normal. Mazda says it's not coolant, but God, that can't be normal for our cars. It was about 10 degrees Celsius when that was taken.
Does yours look like that video when you start it cold in the morning in the fall??

[maderd]

The one thing that really puts doubt in my mind is that the exhaust was very sweet smelling. That's supposed to be coolant. But mazda says it's not.

[Milan96]

Hey man
Thanks for the reply.
I've had the car less than 3 weeks and this happened within the first week. I didn't notice it(or it didn't happen) for the first few days, but I did notice some white smoke a in the rest view after an hour run on the highway... And that got me looking into it.
I've never seen a car produce what is in my video and be normal. Mazda says it's not coolant, but God, that can't be normal for our cars. It was about 10 degrees Celsius when that was taken.
Does yours look like that video when you start it cold in the morning in the fall??

It does seem like quite a lot but my car also shoots a ton of white smoke
out initially on cold start up and then goes away after the engine RPMS settle, just like in your video. Your video looks similar to my car. Based on that and the fact that Mazda tested your car and determined there was no head gasket leak (which I would have seriously doubted there would be on such a new car that's generally very reliable), I would chalk it up to being normal. Im also pretty sure these engines purposely run really rich on start up to warm everything up really fast, so that might also contribute to what you see. I wouldn't worry if I were you. If I remember to, I'll record my car as well to show you

[maderd]

Thanks man, that would be awesome. If you can, tahr a wifi whiff of it. The white smoke smelled very very sweet, hence my worry of coolant
Cheers man

[Milan96]

Thanks man, that would be awesome. If you can, tahr a wifi whiff of it. The white smoke smelled very very sweet, hence my worry of coolant
Cheers man

Remembered to take a quick video this morning. Looks pretty much the same. Don't worry about it, seems normal.
https://youtu.be/9IDiORCjXw4

[maderd]

Remembered to take a quick video this morning. Looks pretty much the same. Don't worry about it, seems normal.
https://youtu.be/9IDiORCjXw4

wow...that is in the ballpark - a bit less, but still way beyond what I would think was normal.

One final question. If you were driving around for a while, and the car was defintely warmed up (like after an hour highway run). If you stopped at a stop light or something, would you still see smoke (not as bad mind you, but certainly visible in the rear view). This happens to me. If I gun the engine a bit, I get much more even after its completely warmed up.

Thanks again BTW for taking the time to do that. Makes me feel better! Still think it doesn't look right, but hey, I'm no mechanic!

Cheers

[maderd]

also, do you have a 2.0 skyactiv or 2.5?

[morganc]

It's normal for cars to do that. The first goal of a cold start is to get the catalyst nice and hot so that emissions can be effectively treated asap; the ECU does this by dumping excess fuel. The sweetness will be from excess hydrocarbons that aren't being fully burnt. A persistent coolant leak would give you white exhaust all the time.

[Milan96]

also, do you have a 2.0 skyactiv or 2.5?


2.0 Skyactiv. Had a 2.5L but traded it in recently for this car.

[Milan96]

wow...that is in the ballpark - a bit less, but still way beyond what I would think was normal.

One final question. If you were driving around for a while, and the car was defintely warmed up (like after an hour highway run). If you stopped at a stop light or something, would you still see smoke (not as bad mind you, but certainly visible in the rear view). This happens to me. If I gun the engine a bit, I get much more even after its completely warmed up.

Thanks again BTW for taking the time to do that. Makes me feel better! Still think it doesn't look right, but hey, I'm no mechanic!

Cheers

When it's colder outside yeah. In the summer time there was nothing. I think you can put your doubts to rest, enjoy the car!

[Jackal]

2.0 Skyactiv. Had a 2.5L but traded it in recently for this car.

Should have kept your 2.5. The smoke doesn't look normal. I checked my exhaust and it didn't look like that. I have a 2010 GT 2.5.


Sent from my iPhone using Tapatalk

[maderd]

It's normal for cars to do that. The first goal of a cold start is to get the catalyst nice and hot so that emissions can be effectively treated asap; the ECU does this by dumping excess fuel. The sweetness will be from excess hydrocarbons that aren't being fully burnt. A persistent coolant leak would give you white exhaust all the time.

I know all cars have condensation out of the tailpipe when cold...I've just never seen anything to this degree and was still normal. I've owned a few mazdas, a nissan and a mitsubishi and nothing even close to this. BUt it is obviously how these engines are - that's the take home message so I'm happy

[Default User]

I would start with a compression test

[Milan96]

Should have kept your 2.5. The smoke doesn't look normal. I checked my exhaust and it didn't look like that. I have a 2010 GT 2.5.


Sent from my iPhone using Tapatalk

The 2.0 skyactiv and the 2.5 MZR are wildly different engines. That's a very strong assertion given the evidence provided in this thread that this is completely normal for the skyactiv engines.

[Default User]

Google valve seal failure symptoms

[Milan96]

Google valve seal failure symptoms

If you watch the video you'll notice the smoke isn't the typical blue-white smoke that is noted when you have valve seal failure. Also 0 oil consumption in my car. Thanks for your concern though but looks like it's fine

[Ben_]

Mine 2.0 non skyactiv 2010 does similar smoke on cold startup, especially when she sleeps outside.

Dont worry if this disappear when the car is warm, almost every gasoline engine car I got where doing similar on winter cold startup

[maderd]

Mine 2.0 non skyactiv 2010 does similar smoke on cold startup, especially when she sleeps outside.

Dont worry if this disappear when the car is warm, almost every gasoline engine car I got where doing similar on winter cold startup

Mine still has smoke when warm - not nearly as much, but there is definitely still some there..... Idling at a stop light or whatever.... I'll see it in my rear view sometimes. I've only had the car for 2 weeks, so it's been less than 12 degrees Celsius here for the most part.

[Ben_]

Coolant leak in the engine would cause white smoke almost all time. As far as I know (and i'm not a mechanic), you can check the following if you need
- oil should be brown, transparent clear. If it yellowish or opaque there is water/coolant in it, not good
- coolant liquid level should be stable all the time, verify it once every few days to see. On my mazda tells to change it every 10 years (EU version), so no way the engine consumes it
- when cold starting open the coolant tank and let the engine warm up a little, there should be no bubbles poping up

If not of the any, could be accumulated moisture or water in the exhaust if the car was parked outside that evaporate and produce that white smoke you see only when stopped.

[maderd]

Yeah I had mazda check it out. They say no leaks in the cooling system. Today mine was much less than the video i posted, but still more than any other car I have ever had. I think it's just normal for this engine.
They actually started a mazda 3 sky Activ for me on their lot and it smoked about as much as mine did today.
The smell of the exhaust was identical to the smell of the exhaust from my car.. Which is a good sign.