S14 with SR20det smoking problem

[polishprince]

Ok first of all, hello to everyone, i have roamed here for a bit and just joined since i got my car about a month ago now. I am pretty new to a lot of this but here goes.

It is a 1995 240sx LE with an s13 redtop. I bought it this way so I dont know a lot about what was done to the motor or anything like that but it has a FMIC and K and N filter. Looks like a metal headgasket as well.

Here is my problem. The car has started smoking on idle. It has a manual boost controller on it and it was set high when i first got the car. The boost according to the boost gauge was at nearly 14psi.

I have since turned down the boost to the stock 7 but here is the situation...

It does not smoke when i first start it. After a few minutes of driving it starts to smoke like crazy at idle... looks like whitish smoke coming out and there is a lot of smoke. As i start driving, the smoking stops. Also, after a bit of a run on the highway, the smoking at idle does not occur anymore. I think the car is running rich as well because of the gas smell out of the exhaust.

There is no coolant in the oil or anything like that and as i mentioned, looks like a metal headgasket so i dont think it is that. I had a buddy of mine change the plugs yesterday and he said that they were not fouled. There was some soot on them but they looked ok. there was no oil or water or anything on them either.

Sorry for the long read but i wanted to be as detailed as i could be. I have read that it may be the turbo and a mechanic said its probably my rings so im hoping that you guys here could shed some light on this.

Thanks in advance.

[carmo]

Check the PCV system before you go rebuilding anything. Is there an oil catch can or anything? I don't know too much about those engines but a leak down test or compression test could give you some indication. However, if the oil control rings are no good but the compression rings are, the compression test won't be very conclusive. Good luck and welcome to Nico

[s13erm]

same with the post above. double check your pcv system, make sure your hoses are properly coming out of the valve cover. white smoke is usually coolant, does it have a sweet smell to it? If anything do a compression and possibly leakdown test and tell us what you come back with...

[polishprince]

yeah im going to do the compression and leakdown test this weekend... it smells more like fuel smell... not sweet at all

[polishprince]

ok so i did the compression test today #1 150, #2 150, #3 150, #4 145. And we did the leak down and the results were perfect.. little to no loss. So from what I have been reading, i would guess the turbo. Make sense?

[carmo]

Yea actually. A friend at work has a CA swapped s13 and the "turbo seal" is going out off and on. I know very little about the anatomy of a turbo, but he says his car smokes pretty bad from time to time. Sometimes he can go to redline with no problem and other times he fogs out the people behind him. He attributes the problem to an oil seal in the turbo. Congrats on the good test results.

[polishprince]

Thanks for the reply. I was so worried until last night. A new turbo is nowhere near what the motor rebuild would have cost me. After some reading, i think the gt28rs turbo seems to be a good straight swap into there

[carmo]

You may try to use this as a good opportunity to learn about how to tear down and rebuild a turbo. I know I would. Not so much any machine work, but just tear apart, replace seals and gaskets, check tolerances, end play, and all that stuff. could be fun! If you find a tolerance out of spec, then go from there. Research is half the fun for a car dork such as myself. Plus, it familiarizes you with all the related jargon. The next time someone stars kicking out A/R specs or T3 this and twin scroll that, you can say "dude, you're full of sh*t". Ha! Posers are fun to mess with. Hopefully you have the problem nailed. Good luck and let me know how it goes...

[polishprince]

lol im a noob for now but i would really like to learn so playing around with my old turbo would not be a bad idea.. im just researching around to make sure it is the turbo before i go an spend the money on buying one... from everything i read, it does look like the only thing it can really be is the turbo

[polishprince]

would buying a used turbo be a bad idea? Its a gt28rs and the guy says there is only 8000km on it. seems like a pretty good deal

[navysnail]

if its the turbo seal, there should be oil all over the hot side going down to the IC.

[polishprince]

now i dont know if this is related but when we were doing the compression test we did notice some oil or "weeping" around the turbo on the intake pipe where the intake pipe connects to the turbo...

[carmo]

I'm out of my element at this point. Still interested however.