Well randomly my car will smoke on start up just had my turbo rebuilt so that's outta the question. I have a breather in my valve cover also. It's only on start never after that I checked compression 155-160 across the board. Its a white off blue smoke checked oil still normal looking. What could it be I have a screen on my turbo some people say that can cause it I'll be changing that out tomorrow
Also when I shut it off smoke will like billow guess you could say out my exhaust it'll just slowly flow out

 

Perform a leakdown test. You need a real filter, not just some crappy screen. If you think a street car will survive with a screen, well, you're about to learn an expensive lesson.

 

What do I need for a leak down test

 

Im in the same boat same compressin as well. I have both lines coming from the valve cover back to my intake. I get a puff of black smoke after I do a wot to redline

 

Black smoke is fine. Thats just fuel. White smoke isn't, thats oil. If he had a new engine I would say assembly lube/valve seals. Prob turbo again tho. Running a screen on a turbo is for race applications only.

 

Do you pray? if not, i would suggest starting because it sounds like you have bad internal problems...gl

 

Xtreme Motorsports Cobalt SS Dyno - YouTube

here a youtube video of my dyno pull

 

Yeah, that doesn't look black. Turbo seals possibly though. If it were rings it would do it during the whole pull. Valve seals would do it during idle. I wouldn't worry too much though until it starts smoking at idle.

 

guy i know drives a civic with open turbo, and thats like almost down by the ground. cause of 15 hp loss he refuses to put a filer on, still chugging away years later. dont know how he manages to not break ****

 

white smoke is coolent, blue smoke is oil

 

looks like normal gray smoke to me

 

The thing about this video that bothers me is that you're getting the whitish/grey smoke after a pull. Typically when you get that smoke at idle, its usually right after starting the car when its been sitting for a while. That is moisture in the exhaust path getting burned up. You can test this by standing behind it and wofting it towards your nose as the car idles. It will not have a smell if its moisture. Obviously coolant will be sweet smelling as the glycol in it is sort of like sugar. This is not to be confused with E85 though as E85 has a VERY sweet aroma.

 

Mine did this both times before sleeve blew

 

Not always. Light white/grey smoke is oil. Blue is oil if you're burning A LOT of oil...Black smoke is fuel. I should know, I've had a few vehicles that smoked, the cobalt was one of them during break-in. Now thick white smoke is coolant...but usually you need to smell to tell the difference.

 

What I've always been told is it's oil slipping past the valve guides while it's sitting. (worn guides)
I could be wrong, that's just what I've always heard.

Smoke while it's running is course totally different.

 

I'll have to check I'm gonna switch to a filter today to be safe and see what happens it'll only do it when I start it and when I shut it off it'll just barely smoke just like a gun after bring shot it'll roll outta my exhaust. I just had the turbo rebuilt like a week ago

 

mines use to only smoke during boost and then during normal driving now it smokes during idle and im talkin like it was 10 degrees outside, couldnt fully diagnosis it, but i thought it was oil seals since i had to keep adding oil to my car. never lost a drop of coolant.

 

I would check the turbo again. It sounds like it could have been a bad rebuild and some oil is seeping by, unless it was doing it before the turbo rebuild.

 

So it seems weird to me even on normal driving if i just shut the car off without even beating on it after driving when i start it up again itll smoke but if i let it sit for a minute or so then shut it off it wont smoke when i turn it on. I drove to a buddies shut the car off instantly normal driving whole way there turned it on to leave and soon as it started up started smoking. Im at a loss right now what can cause this

Also yes it started doing this before the turbo rebuild but precision said they found some oil in the exhaust side of the turbo either from hot shutdown or air restriction they said. I thought it was from so much crank pressure so i installed a breather and itll still do it