Stephen

Penny just dropped, if the front cam cover ones have a one way check valve in place, then at idle this prevents a proportion of the air that is being scavenged into the intake by the pcvs being sourced directly from the intake. The non return ensures that the vacuum sources blow by gasses more efficiently, creating greater sump ventilation. I think I've just managed to unravel that mess of thoughts. If that's correct why the hell didn't Nissan do this to begin with....

I really do appreciate the time your giving me with this one bud ive just done reading into the basic principals of crank case ventilation and now I understand that the pcv valve on our cars I sthe one responsible to removing oil at idle, and the one going into the corrugated turbo feed pipe is for WOT. This does however confuse me here the whole owv is concerned as sod all goes that way at idle due to the vacuum pressure in the plenum pulling it through that way. God im starting to get confused. In terms of venting to atmosphere only, you then loose the scavenging? effect that helps to remove problems with the crank and gasses that would cause it to chop the oil about. so that is a disadvange isn't it? I think the issue ive got is sort of breather related in that there is bog all backpressure in the exhaust at idle and the pressure in the sump is higher than this causing it to pass. Part of me also questions if my oil level is correct or too high as reading the Nissan dipstick is nigh on impossible I find.

it will be the drive shafts failing next :P

Yeh I'm just wondering if the pcv/crank ventilation is the root cause of your turbo woes. Could save you some serious time by trying it first.

Cheers for that jeff, I can see it being easy on an na, and I really have no idea why I didn't do this when I had the engine on the stand and the manifolds off, I guess I just couldn't see the wood for the trees with the leaky rocker gaskets and assumed it was ok. Lesson learnt.

Is it humanly possible to remove the oil filter tree in a twin turbo model without pulling the block or turbo. Yes I know it will be tight and my knuckles might bleed, but im up for a laugh if its possible. just don't want to waste time on getting frustrated over something that isn't actually possible.

oh and the car is fully decatted with divorced downpipes 2.5 all the way with 4" slashcut rear boxes so is extremely freeflowing, also not helping. the only three things I may have done wrong are, non oem pcvs, non oem ruber from the oil drain(may have shrunk internally) and my oil choice. I am being very picky as I say as the amount of smoke is like a cigarette not a factory chimney lol.

Ok can I ask a few questions on that basis as id been thinking about this in any event, you saying about low pressure in the turbo, I was under the impression that higher than atmospheric pressure in the sump, caused oil to back up/not flow freely into the sump, this then causes excessive oil levels in the turbo and the lower pressure of the exhaust system allows it to suck it out through there? My turbos arn't tired as such, there rebuilt, previously on idle they smoked like a trooper, since the rebuild they have improved 100 fold, and the issue only occurs when the car is HOT ie when you've given it some, then spend a prolonged time idling at the 900 or lower rpm range. I could drive around all day at 2k and youd never know, I could also take you around for 20 minutes on attest drive and you never see a thing, after an hour though it would rear its head, I assume this is because the oil in thinning out, making it easier to pass? I do wonder whether my choice oil has its part to play here.

Yes...go on lol, im currently considering venting the crankcase to astmosphere to relieve backpressure.

Yup, mines removed and it does exactly as noz said. My tubs smoke a touch, I believe, but is disappears completly with the ac on. Do you still have your cats? And are your breathers all in good order etc. have a good read of the thread I put up yesterday. - - - Updated - - - Yup, mines removed and it does exactly as noz said. My tubs smoke a touch, I believe, but is disappears completly with the ac on. Do you still have your cats? And are your breathers all in good order etc. have a good read of the thread I put up yesterday.

Oh no, you dont have to do it from above, thats way worse. The bottom two you should be able to do easy with a ring spanner, the top up with a socket on a uj I believe.

http://www.pistonheads.com/classifieds/used-cars/nissan/300zx/nissan-300zx/1142437 pretty sure its been hiding around my area recently saw it up for sale today.

Be worth getting yourself a finishing tap aswel, and some wd40 clean all the crap out the threads, this will ensure your torque settings are correct, as if they're all crudded up inside it could snag and effect your reading. good luck.

Yeah Its given alot to consider.

http://www.procharge.com.au/turbotorque/6-blog/blog/117-the-turbo-blues/ I don't now how correct this chap is but its an interesting read and probably a good fault finder.

There's one occurring for the sw lot over the easter weekend, would be interesting to get your take on things over the day. im hoping to take loads of pictures and do a full write up on the day anyways.

thought id update this, driven the car a fair bit this weekend, the smoke on deceleration has now stopped. 3rd and 2nd gear overruns from 50/60mph and not a hint.... what I am stil getting a touch of though is that characteristic grey smoke, after prolonged hot idle(cold idle its fine) if your stop start in traffic for example there is a small amount of grey smoke, looks like a cigarettes been left in the exhaust, then if you roll forward and stop you get a small roll of smoke, you can smell its oily, and it clears almost instantly. However if I turn my aircon on, the problem magically disappears. To me this sounds like my rebuilt turbos are still letting by the tiniest portion of oil. However ive still only got 200 odd miles on the clock, since the rebuild. I Think I'm going to consider refitting some sort of cat or extra silencer to build some backpressure back into the exhaust system, the problem is tiny but im a bit picky. All things being equal il be fitting some gt525s in about 18 months anyways, if all goes to plan :) going for new chra this time though not rebuilt ones.

id love an ls1 z32 :)

there is a massive spares place in the states I watched a prog on them, apparently the exterior panels are made from brushed stainless steel, a scratch ding whatever see tha whole panel being re-polished to remove it! I think that one looks quite cool but tbh they were a bit crap, weighed a tonne and were a bit gutless by all accounts 150hp and nearly 1.3tonne that's 2.8 capri power to weight nigh on, bera in mind the capri went out of circulation in 86. Infact looking into it, it is a ford cologne v6 the same v6 fitted to the capri. massive price tag on release old fashioned v6 lump well the styling is a bit tooo robo cop. Looking at the American car market, just 2 years prior to its release Pontiac had released its 79 trans am a beautiful piece of automotive history, seriously if you'd had the cash in 1981 what would you have brought amongst the variety of imports and gmc's offerings. The cars production ran for one year and sold 9000 units, that speaks for itself.

what a stonking little zed!

You can use the japspeed ones, may be a touch tight if its an auto mind. If you were closer id lend you a hand, whatever you decide, if those eblows are coming off bear in mind that those studs might be a hassle to remove, so ensure they are soaked in wd40 or simular in adv as nce of you trying to remove them. Also bear in mind the possibility of the decat showing the symptoms up of leak rear oil seals.

Jimmers not southern, hes practically in the midlands, if you can touch the channel its not south :) - - - Updated - - - Cant I mean damn.

I mean its possibleto remove the elbow, tbh why dont you just fit some proper divorced downpipes etc.

It is possibe just fiddly and you eil need to remove the turbo heat sheilds,therearprotion at least. Ive done this job twice nowin situ and I wouldnt relish a third.

stock t22 turbos? sounds a bit high for them sounds more like bigger turbos