ooops, and need advice.
 

I let my s12 get dangerously low on oil the other day :( totally my fault i know, but there must be a prob for it to be that low!!!!! so i filled it up, now when cold it starts with a bit of blue smoke, as i pull away and boost kicks in, i got some more blue smoke, but clears, once warm the smoke isnt really noticable, BUT you can smell it coming out of the exhaust, so i gather its burning the oil rather than leaking, now ive had both the turbo seals & the valve stem seal go before so i have some idea what to look out for, but this is strange, coz valve seals mainly smoke on hot startup, and very little on cold startup, but turbo seals normally smoke on deacceleration, which it isnt (yet) anyone have any ideas if this is early stages to either the rings, turbo or valve stem seals going tits up, bearing in mind i did the valve stem seals 2 years ago with genuine nissan ones, could it be one slipped off?? the turbo is a T2 hybrid with 360 deg bearing running aprox 10 - 11 psi boost, this was last reconditioned in 2001.

next question is..... does anyone have the parts laying about to bolt a T25, T28 straight on, as money is really short and i cant do another £400 for a turbo just yet, and if i do its gotta be worth it (i.e a bigger one T25, T28 )

Cheers.
Jamie

i had the same problem with my last s12 , i put a hybrid on it in the end aswell as doing the cam belt front and rear cam and crankshaft seals and clutch all at the same time, infact i've still got the hybrid turbo in the loft , its done less than 2000 miles and was run on synthetic only, adjustable wastegate actuator too if you're interested make me an offer:)

What turbo is it?

t2 hybrid by turbo technics 360 degree thrust bearing and all that it wasn't cheap either , i had it set by them to run at 14 psi

Am i right in thinking that the T2,T25 and T28 share the same type of bearing? i.e there interchangeable?

as far as i know yeah

i wonder if its to do with when i took out the metal pipe supply to the turbo, i have the mk1 engine with the long pipe, this broke at the join at the back of the engine, i replaced this with a length of braided hose, i wonder if the join at the back of the engine was a restrictor of some type??? other than that i havnt seen a restrictor in the line when i had it off, could this cause the prob????

The thrust bearing i mean? soz

thats what i mean't :)

Cool surely a thrust bearings a thrust bearing, The reason i ask this is because i have a couple of hybrid T2s and as im building the T25 up i wonder if its worth using the 360` bearing from the T2? Suppose it depends how worn to the thrust collar it is:ghey

normally there's a screw in fitting on the engine block that the pipe attaches to, normally you should drill them out to 2mm ,WARNING, don't go any bigger than that otherwise you'll over feed the turbo with oil and blow the seals in it,when i got my s12 some one had been playing with it under the bonnet but they didn't know what they were doing they drilled the restrictor out too much and blew the seals in the turbo , so while i had the engine out i priced up a nissan one but it was way too expensive (from memory it was about 80 quid, it was a long time ago tho) so i had a local engineering firm make one up for me it cost 15 quid , becareful tho because the bit that screws into the block has a tapered thread make sure they get this right, a bit of ptfe tape and it'll be fine:)

it should fit adz , i don't see any reason why it shouldn't , as far as i know the only difference between the t2 and the t25 is the compressor wheel and housing size and the way they are attached ie t2 big ass circlip and the t25 is bolt on , but i'm sure you know that anyway:)

T25 has a big ass circlip dude:confused: If you mean the circlip that holds the compressor housing on?

the t25 that i rebuilt was bolt on , it was off a 200 sx:confused:

turbo seals are not normally on start up.normally they are either on gearchange or at idle once hot. remove your oil filler cap and see if the engine idles properly still or if it drops significantly( a slight drop is not too bad). You could have lots of oil pushing through your rocker cover breather pipe and back through your afm to turbo inlet pipe.

There is 4 bolts that fix it to the exhaust housing then a large snap ring is used to hold the turbine itself onto the compressor housing.

ill check the breathers when i get a chance.

mine being a mk1 engine it doesnt have the supply from the side of the block like the mk2 engine, my feed comes from the oil pressure switch T adaptor on the other side.

**edit** i just started it up, it had a small puff on startup, i mean the instant the engine started, then was clear, but smells still of buring oil, what ever is going could still be in very early stages

that could well be it you know, like i said it was a long time ago , 10 years or so:o