I try!

What size restrictor do you run on your T25?

 

That motor had like .015" cylinder wall wear and would blow the PCV valve out of the valve cover from all the blow-by......Good times.

 

I bought mine from a local performance shop but I think there's only one size fits all:
t25 turbo oil restrictor eBay

 

That is impressive!

 

UPDATE: The smoke is worse and is now also happening pretty much all the time. Sometimes worse than others. The turbo is blowing oil past the seals for some reason. The image below is after running it hard. I think it may be turbo oil drain related. Could someone with more experience tell me if my oil drain line is horizontal for too long (second image)?

 

Going back to the original post , " white smoke " says coolant not oil to me. I vote for head gasket. Fredb

 

I completely forgot to add in the update that the smoke is without a doubt oil smoke, not coolant smoke. Since it is now occasionally smoking at idle I am able to see the smoke without looking through the rearview mirror. While it is not the same blue that you would typically associate with oil smoke, I can smell it and know that it is smoke from burning oil.

I read somewhere that oil smoke that does not go through the combustion process (goes straight to the downpipe from the turbo) is not always blue. I think that is what is happening here. I am going to make a new drain line that does not go horizontal like my current line does. If that does not fix the problem I guess I will be looking at using a restrictor even though that is supposed to be a last resort type of thing for journal bearing turbos...

 

I took my oil drain line off because I am going to make a new one that does not go horizontal at any point. I found that the ID of the -AN line fitting is 3/8" even though it is a -10AN line. Does anyone know the standard ID of this fitting? I am using commercial lines on my car that may not be standard. Also, my drain line is a nylon braided line, not stainless, so I think the rubber may be thicker = smaller ID.

 

UPDATE: I made a new -10AN oil drain line that does not go horizontal at any point, it still smokes blue a lot.

Next, I installed a pop rivet restrictor (takes the ~4mm fitting inlet and makes it 2mm), it still blows blue smoke like I converted it to run on engine oil.

I am buying a turbo rebuild kit now. I don't know what it could be besides turbo seals at this point...

 

You might try running out without the turbo on for a few seconds to see if it blows smoke before you spend money on the turbo. Just a few seconds of running will tell you what's up, I've wouldn't run it long like this.

 

Just let the manifold open in the engine bay? The only problem would be that I would need to drive it some to be sure that it's still smoking.

 

Yeah don't drive it, I would only idle with it pointed at the shock tower. With that much smoke I betcha you'll be able to tell if it's pre or post turbo on disassemble.

 

That's a good point. Dry manifold and wet turbo would mean turbo problem and not engine problem. Based on what I've tried so far, do you think I can confidently say I've narrowed it down to either an engine issue or turbo seals?

 

I would think so, that's about the only way to get oil smoke.

 

I know this has been beat to death at this point, but I would like to add a little experience story.

I boosted my Honda insight that had 300k miles on the original motor/trans. It smoked like a chimney from day one, I assumed it was the Ebay GT12 that just had bad seals, because the car never smoked before, so I just kept driving it. 50k Miles later my hybrid battery died on the car (unrelated to the turbo) so I decided to give the entire system away to a friend who I owed money. Guess what? He put it on his car and it only smoked while the old oil burned off. Since then, it has never smoked.

 

Thank you for all of your help on this!


Thank you for the insight. I really hope this isn't an engine issue. I have a hard time accepting that it's an engine issue because it did not smoke or burn any oil before this build. Also, even when I only run 2 or 3 psi, it still smokes just as badly as it does at 10. That makes me think the smoke is proportional to oil pressure (RPM) and not boost. Which suggests a turbo issue to me.

Honestly at this point I'm just hoping I do not have to pull the engine again. Because if I have to rebuild it then I am going to build it for real which will mean a lot more money and time.

 

The manifold is dry. I have not gotten the downpipe off yet, but I am hoping from the downpipe it is obvious that there is oil post-turbo but no pre-turbo.

 

Well, when I pulled the turbo off, the engine no longer smoked. So... Yea.

 

Wait so the engine did not smoke before or after the turbo was on but it did smoke with the turbo? Then your friend used the same turbo and it did not smoke?

 

I had a similar issue that progressed like yours(first just smoking when getting off throttle then started always smoking after a few hundred miles). I checked everything, oil restrictor, oil drain, etc. The telling sign was that smoke/oil started coming out of the crank vents due to a bad cylinder and had so much pressure you could see pulses of air oil coming out the vent filter. I did not see if you said you checked compression but that was the final indicator. Mine was 3 cylinders where in the 160psi range and cyl 3 was well below 100psi.