Mystery Smoke on Cold Start

Hi all,

Looking for some input on a recent issue I'm having with my '22 TRD OR with 45K miles. On cold starts, especially after the vehicle has been sitting overnight, I am experiencing a large amount of smoke coming from my exhaust. It seems mostly white, MAYBE with a hint of light grey/blue, but very hard to tell. Smoke stops as truck warms up and only lasts about 20 seconds or so. Not coolant, as there is no sweet smell and coolant level is steady.

Dealer says the truck is not throwing any codes. Dealer also originally dismissed this as "probably condensation," but that doesn't make sense considering the frequency of this happening, the amount of smoke and the climate I live in. Dealer agreed to keep the truck an additional day and cold start it again. Upon seeing more smoke, Toyota recommended doing an oil consumption test (essentially marking oil level, having me drive ~1,100-1,300mi) and seeing if there is an abnormal decrease in oil level.

My thoughts are worn valve stem seals or bad PCV valve. If one of these things were the issue, and if I am only seeing this smoke upon start up, would it even be burning enough oil to show a decrease in oil over 1,300 mi? Any other thoughts as to what could cause this? Curious to hear your thoughts.

 

At cold startup? It is probably condensation, but definitely a good idea to watch oil consumption.
If it was something other than condensation (ie oil) you could smell it at the exhaust.

 

@Chew cold just meaning when the engine has been off for a while. Ambient temperatures by me are warm, seeing a lot of condensation is not typical on start up. Smells slightly burnt.

 

Did you just get the vehicle? You don't say where you live or what the temperature outside is on cold start up. Where I live if you start a vehicle when temperature is below freezing you will see "white smoke". It's combination of hot exhaust meeting cold weather and also some condensation. I would monitor oil consumption and monitor other things in general before chasing anything with a dealer. Exhaust has a smell to it as it's a gas burning internal combustion engine.

 

@canuck guy I've had the vehicle since 2022 as the original owner. I'm in Southern California, temps are in the 60-70s right now. I'd be much more inclined to believe it was condensation if I lived in another climate, but this happens in warm outdoor temperatures to the point where neighbors are like what is wrong with your truck when I start it up.

 

Ahaa. Well probably not cold weather "smoke" or condensation.
Could be a number of things including valve stem seals.
Hopefully it's still under warranty.

 

What is the outside humidity and has it changed recently? Combustion creates lots of water vapor, at 60f it is certainly cool enough to create ''smoke'' [water vapor/steam] when a cold engine is started before the cats light off. Do A/C and do dew point adjustments on a psychrometer and it'll sometimes surprise you at the adjusted temps. Add to that the fuel mapping is rich to begin with as cold engines don't combust fuel as efficiently as one that is warm. Once the engine warms up, mapping switches over to being read and adjusted constantly.

 

@canuck guy It is still under powertrain warranty, that's why I decided to go the dealer route. According to Toyota, the next step is the oil consumption test, but if the oil consumption test does not show signs of excessive oil consumption, powertrain warranty will supposedly not cover whatever the step after that is. I'm wondering if it is a small valve stem seal leak, if it is even burning enough oil to be noticeable on a dip stick after the 1,300 miles they want me to drive.

 

Does it burn oil or not?

 

@BillF1564 Testing that now. Filled oil yesterday, marked it, and will be checking again after 1,300 miles per Toyota recommendation.

 

Mine does this almost year round. It doesn’t burn or smell funky. But it’s worth mentioning today’s weather is a bit lop sided compared to most of the country.

 

Mine does this too (minus the blue/oil part). Goes away after about 8 seconds. I really do think it's just condensation and maybe unburned fuel or something as the engine starts up and flushes out what's in the exhaust. My truck has been well taken care of, and runs perfectly.

 

The 3rd gen seems to generate a bit more condensation than other vehicles I have owned. I always know when the dew point is unusually depressed because I can see it in my mirror.

 

have a video of it?
Did this for a living.....

 

I have the same thing.. I live in Missouri though it does it on cold start only.https://youtube.com/shorts/qv-VgxO60Bs?si=Gc0VRvOuA6r7zLGw

 

still moisture burning off in the exhasut.

 

Update: After driving the truck roughly 1,300 miles the truck failed the dealer’s oil consumption test and it is in fact burning oil. Now the question is, is oil leaking by the PCV, stem seals, or something else…

 

Doubt you'll get a definitive answer on a forum.
Need a hands on analysis.
If i were to guess it would be valve stem seals.
So a month after initial dealer test said no issues now there is one ?
I'd be using a different dealer or shop.
Surprised you couldn't smell oil in the exhaust.

 

warranty?
Hope-so....
Hopefully you have a good tech & if its internal, he can trick toyota in getting you a long block & be done with it....

 

@canuck guy Yeah there wasn’t really an initial dealer test, it wasn’t throwing any codes so they said “no problem here!” It wasn’t until getting on the phone with Toyota corporate that I started getting any traction and they ordered the oil consumption test. With a second dealership now.