2020 6.6 gas rough idle at start

[greatmizzou]

I cant imagine a rough idle being normal for a new engine, even if it is a little cold out

 

5,500mi gas 3500hd cc

 

noticed it last week, start truck at slightly below freezing and it had trouble keeping a steady idle, felt like it was about to stall.  Problem went away after driving 15 miles.

Engine also took several seconds to start from cold, highly unusual.

 

It did it again when temps were 40 out, Long time for engine to start and felt like rough idle.  
 

no codes thrown as of yet

[SkidooSteve12]

Do you buy gas from the same gas station or different ones?

[greatmizzou]

6 hours ago, SkidooSteve12 said:

Do you buy gas from the same gas station or different ones?

Different ones and the last fill up was at a different station from near empty to full

 

There are two gas stations I normally use and this last one was one I have not used before

Edited February 28, 2020 by greatmizzou

[greatmizzou]

Well no clue what to make of it. Situation seems gone now, wont be using that gas station again lol

[Ryno12]

Could be related to this.


https://www.gm-trucks.com/forums/topic/235504-throttle-body-2020-66-sierra-service-bulletin/

[greatmizzou]

Update: 15,000 mi and issue never came up again.  Maybe some sort of learning programming issue?  It didnt even rough start when it was below zero and super windy.