Black puff of smoke at start

[jackl4]

I'm still waiting on my 2015 order so please excuse me if I lack street cred but.....The tolerances on these newer motors are very tight. If you've done much engine work, you would appreciate that the motor starts up rich and heats slower than if it were lean. Hence, the black smoke.

 

As long as the smoke is not blue, I'll be happy. JMHO

[14SLTZ71]

Most likely steam. Condensation builds up inside the exhaust after it sits, and when you start the motor, the heat vaporizes the condensation creating steam.

 

But if its HUGE billowing clouds of white smoke....then you have a bigger issue at hand.

Yeah, just condensation in the exhaust. Seems to do it more on very humid nights.

[jvsodano]

has anyone had their dealer pressure test the injectors, or check valve? I'll bet tat is where the problem lies. Mine did not emit black smoike until about 10,000 miles. I'm thinking the injectors are flooding the cylinders and that is what is causing the black smoke.

[Dnt]

Hmm interesting reading on fuel quality I may try some top tier fuel maybe some Shell for a while and see if I notice a difference. I have noticed black smoke several times but will start paying more attention now. The way these modern engines are set up I can see fuel quality as being more critical now. I just hate that I have been using mostly walmart fuel up to now at 29k miles I may have already ruined my engine dagnabit

[Ventilator]

Hmm interesting reading on fuel quality I may try some top tier fuel maybe some Shell for a while and see if I notice a difference. I have noticed black smoke several times but will start paying more attention now. The way these modern engines are set up I can see fuel quality as being more critical now. I just hate that I have been using mostly walmart fuel up to now at 29k miles I may have already ruined my engine dagnabit

I use Shell 87, and don't notice the black smoke. I think some of the trucks are running too rich, and that is where the puff of black smoke is coming from. Even more on the higher octane gas.

 

I get the same thing if I run premium in my Camaro that was designed for 87 octane.

[Juan Cortez]

I have the same problems too. Somebody have gm number ?