smoke at start up 2014 6.2

mcoats · April 14, 2014

Smoke at start up looks dark smells like fuel in garage sometimes worse than others, dealer checked out and said couldn't find any issues, im a GM guy but not happy about this issue.

Gun Designer · April 14, 2014

Smells like gas all the time, or after the start up and black smoke. Maybe leaky injector(s)? Had that type of problem years ago on a 4.3L. Does it do it worse if it sets for longer?

YQatari · April 14, 2014

Yup, my truck does that too, dealer said it's normal!

More details found here:

http://www.gm-trucks.com/forums/topic/158170-black-puff-of-smoke-at-start/?hl=smoke

mcoats · April 14, 2014

Sometimes it's worse when it sits longer sometimes just a little but I hate it, but really love the truck other than that, I have had 6.2 in other trucks but this one really runs great just hate the fact a $ 56 thousand dollar truck does this at start up unless its warmed up.

mcoats · April 14, 2014

Will visit dealer regularly to get it fixed I only live 2 miles away and you might say I spend too much time there because I like GM cars and trucks.

2016 Sierra Owner · April 15, 2014

You gotta take what ole won ball says with a grain of salt. My truck did this when it was really cold out. I have not noticed it since it is warmer and it usually sits 24 hours or more sometimes.

fondupot · April 15, 2014

Not normal. Your injectors are leaking. Do not settle for anything less than the proper repair to bring your truck in compliance with EPA standards.

Dude, shut up. There was a thread just like this before and you did the same thing.

OP, a little black puff of smoke on start up is normal for Direct Injection motors. Its because the injectors are primed have more fuel than needed for idling and driving. So a rich start-up causes a small puff of smoke. Longer periods of sitting make it seem worse because the computer adds more fuel to prime the injectors, since its been sitting longer.

anthony2558 · April 21, 2014

Apparently this is a "normal" characteristic of a DI engine.

I wonder if they (GM) would or is working on a software update to possibly reduce the amount of fuel that is used at start up. Surely this would correct or reduce the amount of smoke.

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mcoats · April 21, 2014

I hope they come up with something I traded a perfectly good 2012 cts v for mine and the only thing that smoked on it was the tires.

dodgehemi0 · April 29, 2014

This is a common theme with DI engines from what I have read. I had an Ecoboost and this was normal you will also get black soot on the end of the tail pipe after a few 1k miles.

anthony2558 · April 29, 2014

Every truck I've seen on the lot, including mine has a puff of smoke when it first starts up. I wonder if they all have leaking injectors.

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Jon A · April 29, 2014

So should the trucks that do not smoke at start up be repaired to make them smoke?

If they are specifically programmed to fire the injectors twice in order to run extremely rich upon cold startup, thus lighting off the cats more quickly and reducing startup emissions (as these engines are), yes. You can't do that without a bit of smoke. As fondupot said, you're clueless. Or perhaps "willfull ignorance" is more descriptive. I guess we shouldn't expect any more from anybody who participates in "owner satisfaction" polls on vehicles he doesn't even own in order to badmouth them....

fondupot · April 29, 2014

Totally false. Not all trucks smoke at start up. Only the ones with leaking injectors or some other mechanical issue. So should the trucks that do not smoke at start up be repaired to make them smoke?

I've said it once and I'll say it again. This is a common side effect of Direct Injection motors. I don't know what I have to do to get it through your head. Either you are stupid, or just downright stubborn.

STOP creating panic on the boards.