Zilvia.net Forums | Nissan 240SX (Silvia) and Z (Fairlady) Car Forum

Go Back   Zilvia.net Forums | Nissan 240SX (Silvia) and Z (Fairlady) Car Forum > General > Tech Talk > Engine Tech

Engine Tech Technical discussion related to all relevant engines such as KA, SR, RB, CA, 2JZ , L24/26/28, VG, VQ, and LSx series.


Reply
 
Thread Tools Display Modes
Old 07-27-2013, 02:48 PM   #1
Croustibat
Nissanaholic!
 
Join Date: Aug 2011
Location: France - Toulouse
Age: 44
Posts: 1,851
Trader Rating: (0)
Croustibat is an unknown quantity at this point
Feedback Score: 0 reviews
Quote:
Originally Posted by joshfng View Post
I've been doing some more testing. It appears as though it only smokes after decel only after I've been boosting which leads me to think turbo (but again no shaft play and no oil in the intake pipes). Also there's no smoke on decel when I've stayed out of boost.
I dont know. But you need to check the turbo on the exhaust side. No play in the shaft does not mean the seals are ok. You checked the intake is ok, but there is another at the exhaust.

Have you, or have you not changed your exhaust system or the intercooler for a less restrictive one less than 4000 miles ago ? If the answer is yes, then it is a turbo seal leaking.

I also have another theory that you will absolutely not like, but here it is: you may have leaking rings. Off boost it is ok, not a lot of pressure to hold (talking about gas pressure during combustion, not boost). Boost comes, rings cant cope and leak pressure to oil pan. Pressure in the oil pan is now superior to pressure in the exhaust => turbo oil goes through the turbo exhaust seal instead of going to the oil pan.

You need to make a dry then wet compression test.


But again, this means oil goes through the turbo exhaust seal. The reason this time is not that the seal is broken, but the way it works; oil will always go where there is less pressure ( that is supposed to be your oil pan ). I think some turbos use another kind of seal that does not care about that, but not entirely sure.

That is the reason why drag cars running with tons of boost have a vacuum pump in the oil pan, as the rings WILL leak during the run, but oil still needs to come down from the head and the turbo(s).


Quote:
Originally Posted by joshfng View Post
The car smokes a tad when it is started cold after sitting all night but after it's warm there is no smoke at idle.
This has nothing to do with your problem. It is called "nightly moisture going through the exhaust".
Croustibat is offline   Reply With Quote
Sponsored Links
Old 07-27-2013, 03:12 PM   #2
joshfng
 
Join Date: Jul 2013
Location: OH
Posts: 23
Trader Rating: (0)
joshfng is an unknown quantity at this point
Feedback Score: 0 reviews
Quote:
Originally Posted by Croustibat View Post
Have you, or have you not changed your exhaust system or the intercooler for a less restrictive one less than 4000 miles ago ? If the answer is yes, then it is a turbo seal leaking.
I'm not sure of this. I've had the car for 3 weeks total. I'll try to find out when the exhaust and intercooler was put on.
joshfng is offline   Reply With Quote
Reply

Bookmarks



Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump


All times are GMT -6. The time now is 07:50 AM.


Powered by vBulletin® Version 3.8.11
Copyright ©2000 - 2025, vBulletin Solutions Inc.
vB.Sponsors
Copyright ? 1998 - 2022, Zilvia.net