[Spongerider]

It sounds like you need to rebuild your motor.

-How many miles?
-What is you compression?
-When is the last time you did maintenance?
-What kind of maintenance did you do?

Grey smoke from the tail pipe sounds like coolant in the engine.

 

[Spongerider]

What are your compression numbers for all 6?

My guess is bad turbos or bad cylinder.

 

[Spongerider]

Need help?Heres a suggestion - sell the car. 300z's are finicky and unreliable. Youll spend more money trying to fix it and keep it runnin then u would starting an entirely new project on a more reliable platform.But,if money is no object,then stick with the z.

I've own a 1992 Z32TT for 17 yrs and I have had no unreliability issues that you are claiming (130K miles, stock motor and turbos). Your opinion is uneducated if your talking about most or all Z32's. Reliability comes down to the owner (motor maintenance) not the Z.

 

[Spongerider]

ew i jus read the beginning thread.Yeah,sell ur car. Low oil pressure = bad engine. Common problem with that model z too. In the wider fairlady the twinturbos are known for burning out,and jus from pickin up what u were puttin down you have one of these problems or both.Sorry bro

It's a common problem? Show me some facts instead of your hear say? Please add useful suggestions instead of irrelevant garble to the poster?

 

[Spongerider]

Of the last 2 gens of Z's before the 350,almost everyone that Ive seen has had its share of engine problems and burnt out turbos.I jus call em like I see em.Now mind you Ive never owned a Z,I certainly did consider it before I got into 240s 8years ago,and from all my research and everyone that ive ever known thats had a Z,its always the same story. Most of these problems stem from individuals doing performance upgrades,ofcourse you wouldnt know anything about that having babied your Z for the last 17 years.

LOL! My car has been on Sport Compact Mag and has done many trips to the drag strip in Fontana, 12.3 1/4 (stock motor and turbos @125K miles, please.)
HP output in this link
http://www.nissanforums.com/z32-chassis-300zx/40324-please-post-your-dynos.html
My 1/4 mile in this link
Z32racing.com - DRAG LISTS

Like you said you never owned a z32 and don't know what you are talking about. Obviously maintenance plays a big part on the reliability of any engines especially the VG30DeTT.

If you really think the VG30 is bad engine then you really need to look at the history of this engine. Five years IMSA champion and winning a 24hrs Le Mans series. If what I just showed you means nothing to you then you truly don't know what you're talking about.

 

[Spongerider]

If your Z has over 100K miles on it it's most likely your valve covers leaking and is a common problem with high mile Z's.