Hi folks, not been on in ages as i got fed up bending over a bonnet fixing yet another problem! Haha. So ive taken the plunge and got myself a 350z. But i still have my baby, and shes crying out a lot of oil through both banks of the exhaust. ?ive had a wee peek about and there is no oil in any of the turbo pipes (inlet and outlet). And the pcv valve hoses are full, i mean full, of fresh oil. So hence the title, is it my turbos that have gone or could it be the pcv system? Or , hopefully, something even easier to fix. The problem just started literally overnight. I had no smoke whatsoever then suddenly it was smoking like a bingo playin chain smoker!

Big deep breath before ur appreciated responses!!

First off mate what colour smoke, sounds like it might be the PVC system fingers crossed.

hope it's not white omg

Aye afraid it is white. Well very thick greyish smoke to be exact. Very oily smelling. Its coming out both sides, if its a turbo seal would that be on just one side or both?

Thanks for ur responses

could be just the one. There is a cross section in the exhaust so it will come out of both exhausts.

 

 

Is it just on tick over or boost aswell??

Oh aye right enough! I forgot the aftermarket exhaust ive got has that x section. Its constant, as soon as u start, when revving, when warm. And it is using quite a bit of oil.

like car.mad said if depends when it smokes, and if your exhaust has a cross in it, is it from hot or cold?

 

one of my turbos is gone, and i get smoke from 1 bank only on idle, when warmed up, but i have completely separate exhausts. not obviously blue but strong oil smell.

mine came out of nowhere too, just started at a set of traffic lights and has slowly got worse.

 

best bet is to change the PCV vales on the plenum, and clear the pipes out, if it stops then great news,

 

good luck.

me and another member who is a mechanic are local bud, in hamilton, we could take a look for you if needed, point you in the right direction

Thanks guys. First off, the smoke doesnt go away. Its as soon as u start and doesnt get better when warm or revved. The car is sorned and at my work in kirkintilloch. Im gettin it moved to my new place in cumbernauld. This week sometime, hopefully!

I thought that white smoke was moisture in the system e.g. Head gasket problems and that turbos and pcvs were bluey/black smoke?

I guess if you remove intercooler pipes under the inner wing cowling and find oil in there would this tell you if the tubs have gone or going!

 

And yes Steams I thought the colours of the smoke was as you state!

Yeah could be water. Remove the sparks and fuel pump relay and turn it over see if it turns into a water fountain feature! The last thing you'd want is to damage the internals through hydraulic lock by running it if it only needs 1 or both headgaskets doing.

I'm having a similar problem so this is helping me loads aswell. Mine seems to smoke (blue) when idle once warm smells olliy but oil level is fine as I check everytime I use it.

that sounds just like mine, cyberbean,

 

i had mine on the ramp and found no oil anywhere in the system bar some coming through the egr pipes, so i came to the conclusion the exhaust seal on the turbo was gone, and leaking oil into the exhaust, hence only smoke from warm, and appears to clear under revs, (increased flow of exhaust gasses dilute the smoke so it appears to clear), also found the plugs perfect so no oil was making it to the cylinders

 

will know for sure next month as my turbos are being replaced lol.

I did think it was more likely a seal as it has been going on for a while and I'm still getting plenty of boost

[1] The PCV valves on 300ZX are none to gum up & jam lots of oil in the hoses meens that they could be jamed open. [blue smoke] repair or replace valves [2] Blue smoke when you start the engine cold can be leaking turbo seals another check is to take the car for a run to get the turbos hot then let it idle for 5mins. then give it a rev to about 5500rpm and see if the exhaust smoke is blue [oil smoke]if so check both pressure turbo hoses for oil on the hose walls,replace effected turbo seals [3] take the oil cap of and check for excisive crank case piston rings blow by. [exhaust blue smoke] to prove do a compression test on all 6 cylinders.[4] Run down a steep long hill with the excelerator off then open up wide at the bottom of the hill [blue smoke]can mean valve guides worn or turbo seals leaking. [5] gray to black smoke is fuel rich mixture. [6] Light grey to white smoke is moisture or water useally cold engine or a blown head gasket,to check gasket relieve radiator cap pressure carefully first then check for lots of bubbles surfaceing in radiator coolent or do a compression check on all 6 cylinders.

A head gasket sounds probable actually. As i had no smoke whatsoever then bang! So ill need to check the compression. Whats the head gasket like to do on these cars? Possible costs?

if you can do it yourself then its not too bad, if its passenger side i've a brand new Nissan head gasket you can have for the price of postage, was given it by my manager and already have a pair in my garage,

Holy thread revival batman!! :batman:

 

A wee update on the car. Good news!! it was the drivers side turbo had legged it, promptly fitted replacement and smoke gone!! Yippee!!! :hyper:

 

But........the car has a vacuum leak. When its ticking over the boost pressure is at minus 7. I removed the plenum a while back and never replaced the gasket :no:

Ive been trying to find the leak ever since. ive removed all the iav hoses and solenoids. changed every hose with new silicone ones and still the leak persists.

So probably answering my own question here, does it sound like the plenum gasket causing the leak?

minus 7 sounds right mate, that's 7 psi of vacuum (if your reading in PSI).

Its still the standars gauge. it used to read -14psi. it boosts to 14psi but sometimes if u give it a good rev it will cut out and run like a bag of spanners