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please bear with me, this is my first turbo motor ive ever owned so ive still allot to learn...

ok so ive got an r31 i bought its just a single cam 30 with an r33 stock s2 turbo (t03 i believe?) i picked the car up mega mega cheap and ive been trying to get it running so i can drop the motor in my daily driver. ive finally got it running and not ive noticed to main issues with the turbo. 1 is that it leaks oil out of the connection for the oil drain fitting (its a proflow or some other decent braided line fitting) while the enigine is running. problem 2. is that out of the back of the turbo (there is no dump or exhaust fitted to it atm) it blows ALOT of smoke and when i let it idle for a while (the car hadnt been started for a while-i have drained the fuel and filled the tank with 98) but when i put some revs into it a few times then turned the car off and let the smoke clear, there was shit loads of oil that had sprayed out the back of the turbo all over the manifold, waste gate and firewall.

now my question is: would the oil seal cause both these problems or would it just be a combination of a dodgy fitting and a leaky oil seal in the turbo? and how hard is it to replace the seal and how much would it be worth for the parts if i did it myself?-im cluey with pulling shit apart and fixing it. or is it something to do with the bearings being clapped out and the turbo needing a full rebuild?

any advice would be great cheers!

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does your oil feed line for the turbo have a restricted (small) orifice? or was the oil line from an older style bush bearing turbo?

BB turbos only need a steady DRIP of oil to keep the bearings lubricated. If oil is leaking from your drain pipe then it means the drain pipe is under pressure, oil is forcing its way through the bearings faster than the drain can drain it. this backs up in the turbo pushes past the oil seals and does exactly what you're describing. that's why BB turbos have a restricted oil entry hole on the banjo fitting.

Check the turbo for shaft play, If the turbo do appear to have over a mm of back n forward play it means the bearings and seals are worn. Else make sure oil drain is not blocked or kinked, and engine is not overfilled with oil.

thanks for the replies guys, checked over the suggestions and the engines full but not over filled, no lines are kinked and there is pretty minimal amount of shaft play, i doubt it would be more then 1mm.

BUT i pulled the oil feed line off- its an aftermarket braided line and im not sure it would restrict the flow as much as your talking about.

does this look right or do i need to replace the nipple in the turbo with one with more restriction?

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do you have the ventilationn plummed up right. if your motor was N/A origionally maybe there might be a problem with the motor pressurising under boost cos there is no breather or (like factory setup) return to intake from the rocker cover. this could/might cause your symptoms.

Edited by PaulosECR33

Also just to check what size is the drain back? and it runs down hill all the way? They are gravity drained and any up hill at all can cause the cartridge to fill and leak.

I take it that the engine runs well and that you have done a compression test? Its not a case of bad blow by pushing oil out the breathers and into the inlet?

do you have the ventilationn plummed up right. if your motor was N/A origionally maybe there might be a problem with the motor pressurising under boost cos there is no breather or (like factory setup) return to intake from the rocker cover. this could/might cause your symptoms.

quite possibly an issue, motor was originally NA and now has a catch can hooked up and also has a custom forward facing plenum with multiple vacuum nipples out the side, i shall try dicking around with them.

yeah it's not much of a restrictor. also check that there's nothing blocked in the drain pipe.. but I'd say that nipple is designed for a bush bearing turbo not a ball bearing.

how smaller hole should there be?

Also just to check what size is the drain back? and it runs down hill all the way? They are gravity drained and any up hill at all can cause the cartridge to fill and leak.

I take it that the engine runs well and that you have done a compression test? Its not a case of bad blow by pushing oil out the breathers and into the inlet?

drain back is about 20mm internal and down hill all the way. havent done a compression test, the guy i bought it off said the motor was still running perfect when he started putting all the turbo gear on then got a notice from the council to move the car in 10 days, so i kinda took it for granted, but probably wouldnt hurt now that you mention it..

gives me a few ideas to work on tomorrow, cheers again guys!

how smaller hole should there be?

not sure.. i just remember when i changed my lines in the R31 over from RB20 lines to RB25 lines that the RB25 banjo fitting had a smaller opening on the turbo side.

ok so i had a good tinkering with it today.

the oil drain pipe is WAY larger then the oil feed line and does run mostly down hill but has to enter the block horizontally, im assuming this should be ok given its size? i also worked out that it was leaking due to bodgeyness of install. thread sealed and tightened properly.

but i undid the top connection on it and checked for blockage and theres none, and the hose is empty after running the car so its not blocked.

also i took the lid off the catch can so the rocker cover breather hoses could breathy freely and after i had done both that and fixed the leak the turbo stopped blowing heaps of oil splats out the back, now it just blows lots of eye watering smoke.

BUT when the catch can lid is off (rocker cover breathing freely) the turbo blows a little less smoke and the engine doesnt run rough like it was thru the rev range, it runs smoother and doesnt hesitate and pop as much. also when i muck around with the vacuum line from plenum to fuel reg/ block the spare open vacuum line on the plenum the motor drops a couple of hundred revs at idle.

im hoping it is something as simple as vacuum hooked up wrong and im also not sure what should be happening with the vacuum from the waste gate-to the turbo or to the plenum?

took some more pics. if you can see something wrong with the vacuum set up im open to ideas..

also, im well aware the engine bay looks like a train wreck, the bloke i bought it off was setting it up as track drift hack and was just tryna get it running- and YES that is speaker wire for the tps, low coolant sensor and oil pressure sender :thumbsup:

post-65205-1282716951_thumb.jpgpost-65205-1282716970_thumb.jpg

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your catch can is wrong, you only need on line coming from the rocker cover to the catch can.

then the other line is up to you it can either be vented to atmosphere (just put a filter on the hose fitting)

OR

you can plum it back into the intake, as most factory setups have

the way you have it is causing the crankcase to pressurise and force oil out the weakest link. i had a mate who did the exact same thing, it didnt do any damage but blew HEAPS of smoke and idled high, first thing is to fix that up

the green line is where your black hose should go should you choose to return it, if not then leave it off, and make sure u black of the unused fitting from the rocker cover.

once you have done this let it run adn the blue smoke/ oil spitting should clear, it will take ages though, i cant see anything else wrong good job with it, if any m ore problems let me know and we can start looking at other things it could be but for now try the catch can hoses

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Edited by PaulosECR33
the green line is where your black hose should go should you choose to return it, if not then leave it off, and make sure u black of the unused fitting from the rocker cover.

did you mean plug the unused vacuum line on the intake manifold or referring to the filter on top of the rocker cover?

did you mean plug the unused vacuum line on the intake manifold or referring to the filter on top of the rocker cover?

yeh plug the unused vacuum line.

next remove one of the breather hoses from the cam cover and plug that off aswell, then take the hose from the catch cat to the intake inbetween the turbo and your afm (on the vacuum side). if you dont want to do that just put a breather filter on it, this will stop your crankcase from pressurising, you should also get a dump pipe and plug your o2 sensor in so your ecu knows how much fuel to squirt

  • 2 weeks later...

well in between the long hours at work ive found the time to hack the shit out of the chassis rail to fit the dump pipe in and plug the vacuums etc, its not burning or blowing oil any more, but its still running rough and missing alot and now its blowing blacker smoke, (fuel i think) i let it idle for ages and gave it a good boot full a few times but nothing changed. should the vacuum on the top of the fuel reg be plugged into the vaccum?

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