Black puff of smoke at start

[2happyhicks]

Advertising should imclude shaking, vibrating and smoking...since they are all normal.... Come on GM!!!!

[Yzkiley]

Well I guess its a good thing these trucks have a 160k warranty. If the smoking is normal then I won't worry about it until GM has to rebuild my engine from excessive carbon buildup which will ultimately end in engine failure.

[TJay74]

Wow, some of the responses. Black smoke is going to cause carbon build up and lead to engine failure down the road....lol

 

it is on a start up cycle and it very brief, mine does it as well. One little puff right as it fires up from being cold. As said programming is set to be rich on initial cold start up to get the motor started and the cats lit off. Mine doesn't do it once it has been warmed up on the next start, only after a cold start.

[Pinnacle]

I actually started going to Ford and GM dealerships asking about the black smoke on start up and most say its "not a concern" or its "normal". I, personally don't consider it normal, but most seem to.

[mcoats]

Love everything about my truck.......except the smoke at start up

[MikeNH]

Seen puffs of black smoke on tons of GDI models across different brands. Not something I'd worry much about.

[2happyhicks]

Cold...? 84 deg is not cold...the temperature today late afternoon when my truck belched smoke like an old diesel on a "cold" start up... won't even address the gdi statement. .. Black smoke from any engine is unburnt fuel. . What does unburnt fuel do to cyl walls, 02 sensors and cats? Sure doesnt make them last longer does it?

[Ventilator]

I guess I'm going to have to remote start my truck while looking at the exhaust pipe, as I have never seen this black puff of smoke once in the nine months.

[KARNUT]

Most of you guys would have been shocked back in the carb days. The white pipes in the leaded days would have been just to much. Imagine the agony of pumping the gas two times to set the fast idle.

[Ventilator]

I remote started my truck yesterday after it sat for a few days. I did see a little puff come out the tail pipe, not so black, and dissipated very quickly. This was in the garage, and would not have been seen if sitting inside the cab. I'll check it out again outside on a calm day.

 

KARNUT, LMAO!

[14SLTZ71]

If I could post a picture I could show you the bulletin from gm saying this is NORMAL.

With the introduction of direct injection systems, gm has revised the cold start control system to reduce cold start emissions.

Quicker catalytic converter heating helps meet the ever changing emission requirements and improve fuel economy.

A dual pulse injection strategy is utilized during cold start to reduce the time required to bring the catalytic converter up to operating temps.

This split injection strategy lasts for about 60 seconds on cold start.

This process may cause the customer to see increased black smoke, soot, during cold start and should be considered normal.

There you go problem solved and you are welcome.

Is this what you are referring to. It doesn't list the 14 Silverado/Sierra but it does describe why there is black smoke at startup and it could last for up to 60 seconds. I will try to find the one for Silverado/Sierra.

[Kx250f]

Yes that's it but it did list 14 silverado/seirra. I'm more then sure any dealer will look it up and give you a copy if you ask for it.

[14SLTZ71]

I just contacted Chevy online customer service and

Yes that's it but it did list 14 silverado/seirra. I'm more then sure any dealer will look it up and give you a copy if you ask for it.

I just contacted chevy online customer service and they put me thru to a tech, he would not confirm that this condition is normal on the 2014 Silverado and Sierra. I was told to go to the dealer and let them diagnose the condition. Well let me keep researching.

 

Does the document have a number on it? Can you take a picture with your phone and then post it?

[Kx250f]

Hopefully this works! If it does then here ya go.

[Kx250f]

Hopefully this works! If it does then here ya go.