Hot restart in cold weather observation

[ledslinger]

Was on the interstate following my wife driving her 2000 Chrysler Concorde 2.7 today. It was fairly cold mid to upper 20's. When following her with warm engine there was no exhaust smoke or water vapor. Following a hot restart after pit stops in rest area of approximately 15 minutes, I was surprised to see water vapor out the exhaust for a minute or two after a hot restart.

I would have assumed that the motor didn't get cold enough to do anything other than go right to warm engine calibration and efficiency immediately on restart. Because of the exhaust vapor, I'm assuming it didn't and was in a warm up calibration for a short time.

The car has 145K miles and runs perfect. Got 28 MPG with the car loaded to the gills running over 70 MPH.

The exhaust vapor is common on many cars during warm up, I'm just surprised that a 15 minute shutoff requires another warm up.

 

[aquariuscsm]

I bet 15 minutes in the mid 20s brings the engine temp back down to stone cold again. Mid 20s (at least to me) is COLD!! Brrrr!!

 

[JamesBond]

The engine is probably still warm but the long exhaust pipe gets cold enough for the exhaust gasses to cool before they exit the tail pipe.

At single digit temps on the highway my old town car wouldn't stop puffing steam.

 

[DrRoughneck]

Originally Posted By: JamesBond
The engine is probably still warm but the long exhaust pipe gets cold enough for the exhaust gasses to cool before they exit the tail pipe.

This.

 

[69GTX]

Lots of coolant and engine oil cooling occur at 20-30 deg F in only 20-40 minutes.

 

[E150GT]

yeah I am surprised what cool weather can do. I drove 20 miles the other day before I changed my oil in cool weather and the oil was barely warm. I also noticed the other day that after I had driven all morning all over town and my engine was hot, it only took a short amount of time parked to make the cold engine light go on when I restarted the car.

 

[The motor guy]

lol. Hells mid twenties on my cummins the engine is down to 170 by the time I get to a parking spot. That's why people put blockers in front of the radiator on cold days, helps stabilize the coolant temps and retain heat. Although I have a diesel, not sure on gas engines.

 

[Pop_Rivit]

It's condensation from the exhaust pipe.
Originally Posted By: aquariuscsm
I bet 15 minutes in the mid 20s brings the engine temp back down to stone cold again.

That's a bet you'd loose.
Originally Posted By: aquariuscsm
Mid 20s (at least to me) is COLD!! Brrrr!!

It affects a lot of feeble people that way.

 

[edwardh1]

Originally Posted By: JamesBond
The engine is probably still warm but the long exhaust pipe gets cold enough for the exhaust gasses to cool before they exit the tail pipe.

At single digit temps on the highway my old town car wouldn't stop puffing steam.


this

 

[ledslinger]

Originally Posted By: JamesBond
The engine is probably still warm but the long exhaust pipe gets cold enough for the exhaust gasses to cool before they exit the tail pipe.

At single digit temps on the highway my old town car wouldn't stop puffing steam.


That's got to be it! Thanks I should have figured that out, I used to be a science teacher.

 

[Doublehaul]

Ive seen temps this winter down to -30f...steam from the exhaust on the super duty stops when the exhaust pipe gets warm after 25 minutes or so

 

[Brons2]

Quote:
Mid 20s (at least to me) is COLD!! Brrrr!
It affects a lot of feeble people that way.


Why don't you come down here to central Texas in July and we'll see who's more feeble.

 

[bullwinkle]

Originally Posted By: Brons2
Quote:
Mid 20s (at least to me) is COLD!! Brrrr!
It affects a lot of feeble people that way.


Why don't you come down here to central Texas in July and we'll see who's more feeble.
You beat me to it-here in the North you can always add a few more layers-but in TX, when it's 105F with an 80F dewpoint (east TX), the birthday suit is too many clothes!