home register FAQ memberlist calendar

Go Back   Turbobricks Forums > Mechanical > performance & modifications

Reply
 
Thread Tools Display Modes
Old 12-05-2018, 12:50 AM   #1
Hacksaw116
Board Member
 
Join Date: Aug 2003
Location: Santa Rosa, Ca
Question 1995 940 turbo wagon

Asking the hive mind...

When should I expect the stock oil return line gasket/oring to volcano out of the block and dump all my oil onto the ground?

I had an '87 760T with which I got to enjoy this experience 10+ years ago. Engine/turbo was stock B230FT with a Garett t3. I had also implemented the glorious manual boost controller on this vehicle at a pressure rating I can't say for certain. All I know is it didn't detonate on me at the time The event occurred when I was going to pass a truck on the freeway, and when it kicked down a gear at WOT I saw a plume of white smoke billow behind me as all my oil flowed through the block and onto the asphalt/sprayed along the 3" exhaust.

I RTV'd the s#!t out of a new gasket on that 760 and it held up after that, but that car is long gone now.

Since then, I've recently acquired a decent stage 0 945, and cranked up the boost to 10ish psi (spikes to 11.5-12psi because of the shi#y nature of cheap MBC)

I am basically waiting for the same thing to happen again...

I know it is a known issue, so I'm curious about the details. Is this a "keep the PCV system clean and it's less of an issue" thing or is this a "I should expect this to fail when I push XXX manifold pressure" sort of thing?

Of course I can tap it and thread a barb fitting or AN fitting, but that's not a concern. I was hoping to educate myself and others on the nature of this problematic failure of stock assembly via this post.

Curious what others have to say. Cheers!
__________________
Hacksaw116
Hacksaw116 is offline   Reply With Quote
Old 12-05-2018, 12:59 AM   #2
thelostartof
unbalanced chemical
 
thelostartof's Avatar
 
Join Date: Jun 2002
Location: Apache Junction, AZ
Default

Myself I have never had a oil return oring blow out like that even on my 200k+ mile 350whp car running 25+psi.

Sounds more like a crank case pressure issue.
__________________
Chip Feedback Thread / PM LH 2.4 Chip Prices
thelostartof is offline   Reply With Quote
Old 12-05-2018, 01:40 AM   #3
Hacksaw116
Board Member
 
Join Date: Aug 2003
Location: Santa Rosa, Ca
Default

Which implies piston ring blow by?
Hacksaw116 is offline   Reply With Quote
Old 12-05-2018, 09:06 PM   #4
PromiseRing
We don't even like Volvos
 
PromiseRing's Avatar
 
Join Date: Feb 2014
Location: Missouri
Default

Quote:
Originally Posted by Hacksaw116 View Post
Which implies piston ring blow by?
And/or a clogged PCV system (oil separator box).
__________________
Feedback Thread
Current:
93' 244 m47
93' 245 m47
90' 744 AW70
94' M-Edition Miata
95' Camry auto
Past:
80' 242gt m46
88' 245 m47
92' 940 turbo AW17

Knipex pronunciation: /kəˈnɪpɛks/
The K is pronounced like normal. The upside down e (referred to as a Schwa) is pronounced like "uh".
http://www.personal.psu.edu/ejp10/bl...de_down_e.html
PromiseRing is offline   Reply With Quote
Old 12-06-2018, 05:06 PM   #5
dl242gt
Can play the blues
 
dl242gt's Avatar
 
Join Date: Jun 2002
Location: S NJ, a suburb of Phila.
Default

In all that time did you service the oil separator referred to above? You will want to service it on this 940 if you haven't. I've had these seals fail and they make a mess. Never a failure like you describe though. It's straight forward to replace and if you use RTV make sure you use the special oil resistant type. Like what could be used on a differential gasket.
dl242gt is offline   Reply With Quote
Old 12-06-2018, 10:17 PM   #6
Hacksaw116
Board Member
 
Join Date: Aug 2003
Location: Santa Rosa, Ca
Default

I rebuilt the entire engine in the 87 760, however I do not recall if I did any cleaning to the PCV back then. It is very likely I installed it as it was when I tore the engine apart to get machined. I swear I thought this was a known issue, but perhaps my sources didn't maintain the PCV system either... LOL!

I will do some homework on this and make that a priority for my '95 wagon. I have an IPD turbo cam to slap in as well. Word on the street is that will wake things up a little more, I just need to find/schedule a time to do it on the weekend.
Hacksaw116 is offline   Reply With Quote
Old 12-07-2018, 11:18 AM   #7
PromiseRing
We don't even like Volvos
 
PromiseRing's Avatar
 
Join Date: Feb 2014
Location: Missouri
Default

Don’t forget to check shims after the new cam..

For the oil separator, OE is best by far. Just take it off (way easier with intake manifold off), fill it with diesel, shake the crap out of it, drain, repeat. Repeat until it comes out as clean diesel, then reinstall with a new green viton oring.
PromiseRing is offline   Reply With Quote
Old 12-07-2018, 01:06 PM   #8
Mbeas96
Board Member
 
Mbeas96's Avatar
 
Join Date: Aug 2017
Location: Charleston
Default

Also, of you happen to get a new oil seperator box, be weary of the aftermaeket ones that separate where it is plasti welded together
__________________
Quote:
Originally Posted by Mr.Bill View Post
You are not a man unless you've thrown up at a turbobricks meet.

My build thread: http://forums.turbobricks.com/showthread.php?t=340910
Mbeas96 is offline   Reply With Quote
Old 12-08-2018, 03:38 PM   #9
Hacksaw116
Board Member
 
Join Date: Aug 2003
Location: Santa Rosa, Ca
Default

Quote:
Originally Posted by Mbeas96 View Post
Also, of you happen to get a new oil seperator box, be weary of the aftermaeket ones that separate where it is plasti welded together
I was cheap and got a 30 dollar aftermarket from FCP euro. I will probably swap in the aftermarket and clean the original, and if the aftermarket gives me any issues I have a backup. It should arrive this next week, as well as the viton o rings..

Anyway, went to change the oil today, and it's weeping from the problem area that caused me to start this thread. It seems to be the only source of oil leaking on this car, so crankcase pressure is a concern.



I switched the oil to 10w-30 synthetic high mileage. New mann filter and magnetic oil plug with a new copper seal. It was definitely due for a change, the oil coming out was black as death.
Hacksaw116 is offline   Reply With Quote
Old 12-08-2018, 04:14 PM   #10
PromiseRing
We don't even like Volvos
 
PromiseRing's Avatar
 
Join Date: Feb 2014
Location: Missouri
Default

Just leave the original in there and save yourself the headache of doing the job twice..
PromiseRing is offline   Reply With Quote
Old 12-08-2018, 05:08 PM   #11
lummert
Board Member
 
lummert's Avatar
 
Join Date: Jan 2008
Location: Portland IN
Default

It seems that these become an issue after messing with them.
__________________
Trying to understand stupid people is like trying to pick up a turd by the clean end.
lummert is offline   Reply With Quote
Reply

Thread Tools
Display Modes

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 On

Forum Jump


All times are GMT -4. The time now is 03:37 AM.

Powered by vBulletin® Version 3.8.11
Copyright ©2000 - 2018, vBulletin Solutions Inc.