341am

OK I recently built a d16z6/y8 hybrid. After the initial start up and break in, I went to get tuned. The setup made 260whp at 11psi, yet had a missfire issue at higher boost, and after this is when I started running into problems. Now for some reason it starts to smoke terribly after it warms up.

Some back ground

z6 block
fj rods
vitara pistons
all new seals
basically everything new.

y8 head
crower stg2 cam
supertech valves and springs
all new gaskets and seals

Now I have done a compression check with 180psi on all cylinders, the leak down was less then 2% throughout all cylinders. I am baffled. I changed the valve stem seals hoping that would fix the problem, but to no avail it still smokes. I also switched turbos, and added a catch can. The catch can is ran from the black box with no pcv valve, to the can and then back to the breather on the valve cover. It is a vented can.There is oil in the exhaust and intake. UPDATE no oil residue or signs of oil on the plugs.

Any help is GREATLY APPRECIATED, as i am out of ideas.

Fabrik8

There's oil in the intake? That narrows things down a lot.

Trace back along the intake piping and see where the oil starts. That will tell you where it's coming from. That may not be the cause of the smoking problem, but you should get the oily intake problem fixed also.


I'm assuming you got the engine block honed, and you used new rings...? You haven't said what type of turbo and whether or not you're using anything to restrict the oil flow to it.

341am

The block was honed, and I used new rings...etc. It was assembled by chad at apples machine shop. The turbo is a t3/t04e,AR 50 compressor housing and AR 63 exhaust housing. I'm using a restrictor diameter of .065. I just disassembled the turbo, and the exhaust housing was caked in oil, yet the compressor housing was bone dry. Not sure how the oil got into the intercooler piping, yet it's just a thin film.

Is it possible for the black box to somehow be clogged putting excessive pressure on the turbo seals?

PS. Thanks to any and all that help me! I am at my wits end, with school and work. I just wanna drive my baby. I am also in no way a professional. SO THANK YOU, it is greatly appreciated.

Fabrik8

If the piping has only a little bit of oil, that's not the smoking problem. If the exhaust housing is caked with oil, you're getting oil into a hot exhaust, and that's where the smoking is coming from. If you have too much oil pressure going to the turbo center section, you could be forcing oil past the seals. Also, if you haven't followed good practice for running the oil return line, that definitely doesn't do you any favors either.

Changing turbos won't necessarily show any difference right away if there is already that much oil in the exhaust system. So you could swap in a perfect turbo and still have smoking for a while because of the residual oil.

So let's go over the basics. Describe your oil return line, where it's run, how much higher it is than the oil level in the pan, etc. There doesn't seem to be anything strange about the oil restrictor, so I'm thinking that the turbo seals are shot, or something is wrong with the oil return line or how it's installed.

I'm not really sure what you're describing with the black box and the catch can; that's a hard thing to picture without more detail or ...a picture.

341am

The return line is towards the top of the pan, and I have a flex coil to keep it from kinking.

The black box is the part of the pcv system on the back of the block where the pcv valve was formerly located, I just simply have an open fitting plugged into the outlet on the black box (one that used to go to the intake manifold) with the hose running to the catch can. The other hose off the can is connected to the valve cover. Not sure if that helps.
http://njsr.org/pics/albums/userpics...install_s1.jpg
This is the black box I was talking about.

How would the pressure only blow oil through the seal on the exhaust side?

Fabrik8

Don't know. You're assuming a lot by thinking that the seals are the same, and that the seal failure mechanism would be the same on the compressor and turbine housings. Is there oil in the exhaust manifold or just the turbine housing, and did you buy the turbo new or was it already used?

341am

The turbo was brand new when i bought it, which was roughly 2-3 months ago.

There is no oil or residue in the manifold, or the plunger of the wastegate. I cleaned the turbine housing, the seal looked to be fine, but then again I am no expert. I checked and there is no shaft play, and no wear on the shaft itself. When putting the shaft back in, the seal "clicked" into place which I was told is supposed to happen. So to the best of my knowledge it is fine.

Is it possible for excessive pressure to push oil past the seal, yet not damage it? It seems like if I find the source causing the excessive pressure then I should be golden.

341am

Any one have anymore input.....

99formula

Sorry, I had to!

Seems like a turbo seal issue to me.

341am

lol I put the same thing in HT and someone came in asking "where duh weed at", so I was expecting that. Thanks for your input man.

I have taken the whole pcv system out and im going to do a thorough cleaning, also try to get the return line to the best angle. If these don't work, I suppose rebuild the turbo and see where that gets me.