burning oil, hoping its turbo

[GS ice T]

My car was running fine until I raced a RB20 240sx one night recently. This is pushing 18psi out of a t-25 rebuilt 10k miles ago. I rewired my stock fuel pump and shift at 6k figuring thatd be sufficient enough not to run lean on top of the turbo dropping to 12psi or so up top anyway. Later that night I noticed my bov made a fluttering sound at low boost instead of a "pssst" so I looked in it and noticed the oring blew off the valve. I took it apart and fixed it but didnt change the sound....

The day after I noticed blue smoke floating by me after I came to a few stops after driving a bit. I freaked. I did a comp test and got 170-175-171-175 and thats forgetting to hold the throttle open. I also took the LICP off and only noticed a oil film in the pipe which I figured is normal since my breather is fed back into the intake pipe. I stuck my fingers in the IC and couldnt feel any oil that would have settled in there. The compressor wheel still has almost no shaftplay just like it was went it was put on. A buddy of mine checked the PCV and said it was still functioning properly. Also I let it idle for a while and when I took off it smoked a good bit, but it doesnt smoke at all on startup.

I think I covered everything that would cause it to shoot the blues and I wanna say its the turbo. I'm just used to there being a cloud of blue smoke when a t-25 cant take it anymore like the first time I blew it It's time for a bigger turbo anyway its just that I'd be pissed if I got one but it still smoked.

Any thoughts or other ideas on anything else it could be?

 

[meliketoball]

Do a leak down test.

 

[GS ice T]

I'm not very familiar with leakdown tests but aren't they used for determining where compression is lost if your low on compression? Two of my cylinders are a perfect 175 and the other two are 170/171 which to me is still considered pretty good. I also forgot to hold the throttle open so maybe they are higher than that. Is it possible to be over 175 with a CR of 8.5:1 on a built motor? Anyway, I don't see how it would help if I'm not low on compression, just losing oil, but let me know if I'm wrong.

 

[meliketoball]

I don't even know what I am talking about. Check the shaft play on the turbo if you haven't already done so. If that's fine, then it may be your valve steam seals. eek!

 

[GS ice T]

I mentioned there was almost no shaftplay in my first post. If it was the valve stem seals wouldn't that cause there to be a puff of blue smoke when it starts up? Well, I can constantly smell oil burning with the windows down and its starting to give me headaches, but I can only see it every once in a while coming to a stop, or a buddy only noticed it a few times taking off from a stop. Given that my blow off makes a fluttering sound instead of the usual pssst now I wanna say its the turbo leaking oil into the intercooler and I just couldnt feel it in there. I suppose I'll take the IC off and actually see if oil is in there when I get time. If so I'll finally start the upgrade path to more power and get a 16g and eventually supporting mods to crank things up, but that'll be after I pick up the AWD spyder I'm about to buy

 

[meliketoball]

I remember now what I was meaning to say. Give your car a leak down test to see if your rings are bad. Just a suggestion. And for the fluttering you're getting is probably compressor surge and I'd take a look at the blow off valve; see if the vacuum line is there or if something is blocking the passage of the BOV. How much oil are you losing if I may ask?

 

[GS ice T]

So my rings can be bad and cause oil to come up, but not in a way that compression can go down? I did take a look at the BOV, I took it off and took it apart and put it back together because the oring was blow off the valve, but it still made the same fluttering sound after putting it back on and hooking the vac and pressure lines up. Its hard to say how much oil I'm burning since I have a rear main seal leak that loses a good bit of oil but I'll just deal with that until its time for a new tranny. Again, I've covered about everything I can think of that would cause me to burn oil, given the conditions that it will smoke blue. I just have to pull the IC and check for excess oil in there to know for sure, but I will be stumped if there isnt.

 

[brian9397gsx]

man i have exact same prob on my 2g i have 175 across no leak down basically unmodified only exhaust i have no shaft play and i changed valve stem seals but i have no oil in my ic pipes (aside from light film)

 

[GS ice T]

did this happen all of a sudden like it did to me after a hard race? or had it slowly appeared to the point its at now? i only have a light film in my pipes but i think its only because the oil is being sucked/blown into the engine to be burned, since it is being burned after all. plus the new weird blow off sound... it has to be the turbo. is it making a diffent blow off sound for you as well?