More Exhaust steam on newer vehicles?

[chrisf8657]

I've noticed on a lot of the newer vehicles that when it's cold, you see them with more steam coming out of the tailpipes that never seems to stop. Older vehicles (2010 and earlier I guess) you of course saw it, but it stopped after about 15 minutes or when the engine warmed up.

For example, on my 2019 Chrysler 300, there is a constant steam coming out of the tailpipes even when the engine is hot. I've noticed it on other cars too following them for many miles.

Any reason for this? More condensation produced by the exhaust systems in newer cars, etc.?

 

[ragtoplvr]

Burn a gallon of gas, get about a gallon of water.

A more efficient engine puts out cooler exhaust. And since less fuel is burned there is less exhaust. Better larger and lower restriction exhausts have more surface area to radiate heat. This is simply a case where the exhaust never gets hot enough for the moisture to diffuse before it cools enough to product visible vapor. It is a good thing.

Rod

 

[dadto2]

This ^^^

My Volvo is the same way, despite being a '99. It even does it on cool summer mornings.

 

[KalapanaBlack]

Gosh, my '99 Avalon is a steam machine compared to most newer cars. I haven't noticed an uptick in NEW new designs, but I haven't been looking. I've always noticed how much steam my car puts out, however. Especially on not-that-cold, damp mornings and evenings. I can almost cloud up a line of cars at a traffic light.

It gets better with heat, but it's still much more than other cars. In '99, I think the 1MZ was ULEV-certified. Who knows.

 

[spackard]

Seems the newest cars will have auto stop-start and may shut down the engine at stoplights.
Should put out a nice woosh once they restart.

 

[KrisZ]

Originally Posted by KalapanaBlack
Gosh, my '99 Avalon is a steam machine compared to most newer cars. I haven't noticed an uptick in NEW new designs, but I haven't been looking. I've always noticed how much steam my car puts out, however. Especially on not-that-cold, damp mornings and evenings. I can almost cloud up a line of cars at a traffic light.

It gets better with heat, but it's still much more than other cars. In '99, I think the 1MZ was ULEV-certified. Who knows.


Sounds like a small head gasket leak to me...

 

[CR94]

Originally Posted by chrisf8657
I've noticed on a lot of the newer vehicles that when it's cold, you see them with more steam coming out of the tailpipes ...
Steam is invisible.

 

[gathermewool]

If what's been said is true about more surface area and less heating of the exhaust, I wonder how this will affect overall accumulation of condensation, and, therefore, internal exhaust corrosion.

Also, engine temperature has nothing to do with overall exhaust system temperature. Have you ever seen a police vehicle stationed, idling for a long period of time? TONS of condensation dribbling out of the muffler weep hole.

Originally Posted by CR94
Originally Posted by chrisf8657
I've noticed on a lot of the newer vehicles that when it's cold, you see them with more steam coming out of the tailpipes ...
Steam is invisible.


Not all steam...

I'm going to guess you've never seen an actual low-pressure, saturated steam system leak.

 

[Delta]

I think it varies per vehicle. The GTI barely has any steam whereas the S10 looks like the head gasket is kaput. The Camry and Jeep are moderate.

 

[chrisf8657]

Interesting. Thanks guys

 

[demarpaint]

Originally Posted by KrisZ
Originally Posted by KalapanaBlack
Gosh, my '99 Avalon is a steam machine compared to most newer cars. I haven't noticed an uptick in NEW new designs, but I haven't been looking. I've always noticed how much steam my car puts out, however. Especially on not-that-cold, damp mornings and evenings. I can almost cloud up a line of cars at a traffic light.

It gets better with heat, but it's still much more than other cars. In '99, I think the 1MZ was ULEV-certified. Who knows.


Sounds like a small head gasket leak to me...

That was my initial impression too, especially with a new vehicle. If it were mine I'd pressure test it to sleep better. To me more steam means more condensation in the exhaust system, which needs to burn off and 'might possibly' shorten exhaust system life, a bit.

 

[ragtoplvr]

Ever see a jet contrail? Yes contrail, not chem trail. Notice how they are bad some days and not visible others. Ever see them appear and disappear as the jet traverses the sky? The temperature up there and the humidity varies. Sometimes the steam will dissipate, and sometimes it will condense. If it condenses it is visible.

Spy planes routes would be chosen so there would be no visible condensation over the sensitive area. Anything else is taking a huge risk especially with the U2.

So yes, steam is not really visible, until it cools enough to start to condense. Only certain conditions like cold and high relative humidity allow lots of condensed steam to form.

Rod

 

[Uphill_Both_Ways]

Originally Posted by CR94
Steam is invisible.
Chopped liver:

 

[bullwinkle]

Steam is visible once it starts to condense-look at any power plant and you'll see a cloud coming off the cooling tower.

 

[mclasser]

None of my cars steam excessively, but I've seen a lot that do. I see them puffing when merging on the freeway or pulling into traffic from a side street, so the engines must be cold.

 

[Skippy722]

My 2011 5.7 hemi Durango would always have a cloud behind it, I just attributed it to it being a v8. My 2016 v6 300 does as well, but my Caliber really doesn't. Never thought about it till I read this post lol

 

[CR94]

Originally Posted by bullwinkle
Steam is visible once it starts to condense-look at any power plant and you'll see a cloud coming off the cooling tower.
That's NOT steam, but condensation, as is what chrisf8657 sees coming from his tailpipe.

 

[gathermewool]

Originally Posted by CR94
Originally Posted by bullwinkle
Steam is visible once it starts to condense-look at any power plant and you'll see a cloud coming off the cooling tower.
That's NOT steam, but condensation, as is what chrisf8657 sees coming from his tailpipe.


It's steam. Condensation/condensate is liquid. If it's a vapor, visible or not, it's steam.

 

[Anduril]

My Mustang does this even if it's warmed up if it's particularly cold and humid out. If I can see my breath, I can see the car's breath too. I attribute it to the fact that it's a big engine that probably burns a lot of gas at idle (and produces a lot of water), and it has a lot of exhaust pipe (gases cool a lot, the end of the pipes is never more than lukewarm even after a freeway drive, and the exhaust exits with very little force; there's nothing to push it outwards so the steam floats almost straight up). I don't have any symptoms of a head gasket leak, the steam doesn't smell sweet, and it goes away when it's warmer or less humid, so I've just come to accept it as normal for this engine.