Hi chaps,

 

Been having a issue with my 300zx and wondered if any one could offer any advice please..

 

The car is smoking and I have changed the PCV valves and it is still smoking and I have also cleaned all the breather system. I have checked the elbows coming of the turbos and the down pipes and there is no oil, the car is over fueling slightly after being chipped. It only seems to smoke when you have been driving the car and then stop at lights etc and then you get white smoke with a blue tinge.. if you keep the car at 1500 revs it doesn't smoke... any ideas? If I can't get it sorted soon I'm gona have to sell....

Sounds like rear turbo oil seal failure to me. Try engauging your aircon and see if it still smokes, this sometimes keeps idle high enough to to hide the symptom. Text book symptoms for turbo rear seal failure is grey smoke at prolonged idle once the engine is warm. Before you get too caried away I'd check the oil level, too high and it can prevent proper flow from the turbos, so it backs up and comes out the seal.

 

I know you say you can't see it in the elbow but I doesn't take much to make a mess. The oil isn't being combusted hence why it's not that heavy blue colour. It's merely evaporating out the turbine housing. What are your vac numbers reading at idle? Have you preformed a compression test? I ask this as excessive blow by can also cause the oil to not glow out the turbo correctly.

 

It's a bit embarrassing isn't it. When mine started that a lady started shouting at me saying my car was on fire...

I agree with Steve, hope that it's an easy fix :clover:

Thanks for the info Stephen yes it's embarrassing and yes I do have the heater on some times. Number 4 cylinder is down a bit on compression test. I'll check the oil levels and post