First post and it's a question......

502 · Feb 13, 2017

Just found this site and have searched the forums but haven't found an answer. I just traded my 1996 2500 5.9L in last week for a 2017 3500. Wow, things have changed a lot since 1996! I bought that truck new and put over 350K on it. The 3500 is quite a different beast though and I pulled my tractor(about 4500lbs) to a job this morning for the first time with it. My question is, when I pulled out on the highway this morning and started accelerating, a LOT of white smoke was coming from the exhaust. It took about 5 minutes of driving for it to go away. My 1996 never did that so I wasn't sure what to do. The truck was running fine and there didn't appear to be any problems but the white smoke. Has anyone ever had this happen with a new 6.7L before?
Thanks in advance!

07MegaCabRam · Feb 13, 2017

Wonder what the exhaust temps where when you were pulling. Could have put some water in the exhaust.

502 · Feb 13, 2017

The truck was in my garage overnight(about 55 degrees). It was 40 outside when I hooked up the trailer and when I went down to the highway, it was 32 down there. I thought it might be the temperature causing it because as the truck reached normal operating temps, it went away. Just had never seen white smoke out of my old one and want to be sure it's not a problem with the new one.

Tach_tech · Feb 13, 2017

Likely just condensation in the exhaust, see this a lot when they're still cold for the first few minutes. Nothing to worry about.

GsRAM · Feb 14, 2017

As your probably fully aware, there's a lot more electronics and emissions bs on your new truck. I'd agree with the others, likely condensation combined with ambient air temps. Your new truck runs a lot cleaner than your 96, so that may have something to do with it.

Now if it does it in the middle of summer, i may be concerned. But i doubt it will

Marciel · Feb 14, 2017

I bet it is something to do with the def system, my girlfriend's korean durimax will do that occasionally and there is nothing wrong with it other than its a gmc.

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7777xm · Feb 14, 2017

My 07 power stroke would do the same from time to time

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502 · Feb 14, 2017

Hauled 2500lbs in the bed today with much warmer temps and the truck was warmed up before it got loaded. No smoke of any kind. What a difference the 6.7L engine is over the 5.9L. Along with the Aisin, exhaust brake and
air bags, I couldn't really tell it had that much weight in the bed. Although, it's pretty depressing having a "current mpg" gauge in sight when climbing hills or getting on the freeway with something that heavy in the back....

JRG18 · Feb 14, 2017

The SCR system injects DEF into the exhaust stream converting NOx gases to Nitrogen and H2O. When your exhaust is a certain temperature it hits the cold air outside, and along with relative humidity and atmospheric pressure, the water saturates the air causing visible water droplets (similar to cloud formation). Once you're at operating temperature the temp is too high and causes the water to dissipate more rapidly. :happy107:

Each morning when it's cold mine does if for a little bit of the drive usually when I'm about halfway to operating temp or so.

First post and it's a question......

502

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07MegaCabRam

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502

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Tach_tech

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GsRAM

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Marciel

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7777xm

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502

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JRG18

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