SR20DET - Air pulsating out Oil cap hole & Smokey Exhaust Occasionally, Help!

[got2b240]

Sometimes there will be smoke that smells kind of like oil burning off thats dark greyish in color that doesnt dissappear when it hits the air, it kind of stays in a smoke form and floats off with the wind out the exhaust.

I figured its my turbo cause it happens only at idle. I never get smoke when I drive. And it takes a couple of minutes at idle for this to happen when it sits idling, and sometimes it just wont happen at all. It comes and goes.

I had 2 previous SR's in a 240 I sold recently, and the last one did the same exact thing with the smoke out the exhaust but I never checked the Oil cap for air comming out, but someone told me its most likely the turbo, when it smokes at idle. So I figured thats what this is.....till:

I opened my oil cap when it was idling tonight after a hard run, and there was Pulsating air comming out the valve cover!!! What does this mean?

I have searched, and I found nothing that settles my stomach with this mystery

[NISTECH]

Think about something for a second. When the piston goes up what happens on top of the cyl with the air above it? When you figure that out think about what is going on under the piston when it goes down. Hint: the air under the oil cap is in the same enclosed area as the air below the pistons.

The smoke out your pipe could be due to turbo but it could also be as a result of a rich running conditions. When you gas after it starts bellowing out at idle does it make the cloud much bigger and eventually tapper off or does it imediatly stop upon hitting the throttle.

[got2b240]

it blows out a little bit more and then goes away

please give me your advice

[NISTECH]

That sounds like a turbo issue then. If it were rich it usually goes away pretty quick, It belts out the excess pretty quickly, were oil from the turbo takes a little while to burn off. I have seen this on the twin turbo Zs before. Mind you though I am no turbo expert. I dont get the oppurtunity to work on them hardly at all.

[got2b240]

dude thank you soo much for your input and insight.

With the way the world is today, you wouldnt think people could be this helpful as you have been to me.

Thanks again,

Chris

[s13sr20chris]

pulsating air from valve cover with oil cap off. yup, check my members rides gallery for pics of my BROKEN PISTON!

my car ran great on 3 cylinders.