[Vwdiesel] PCV operation;blowby and runaway

[LBaird119 at aol.com]

In a message dated 5/26/2006 8:21:11 AM Pacific Standard Time, 
quantum-man at hotmail.co.uk writes:

> I expected people to jump in and  say what's the Limey talkin' about? 
> Dohhh...

  Don't feel bad Mark.  We still do wonder that exactly, just maybe not 
THIS time!  ;-D

> 
> The semi blocked cam cover grating may be quite crucial:
> If the sump pressurises beyond a few psi then overcoming gravity may be easy 
> 
> especially if the pipe is nearly full. Won't the area near the intake side 
> turbo bearing be atmospheric at tick over and at vaccuum with turbo fins 
> scavenging enough air centrifugally to supply say 10 psi. Indeed maybe a 
> 'syphoning' effect Andrew (;o)...
> 
> 

  Ahhh, good time to point out WHY a turbo return line is supposed to 
have a free drop ABOVE oil level, with no sags in the line.  If it's clear 
then the oil WILL run out and crankcase pressure is irrelevant.  IF there's 
a bubble of oil in the line or the line is below oil level, then pressure 
could 
push the oil back up the tube.  Still, until the tube is full of oil, the 
supply 
will drop and drain.  It's doubtful that much air (blowby) would go past the 
seals on a turbo.  Oil under pressure though...  They use slingers etc to 
keep as much oil away from the seals as possible.  Not really designed to 
hold back pressure to speak of.
     Loren