[Vwdiesel] Blow-by test?

[Marco]

As I understand things, and others may have a different interpretation, if the 
pistons/rings/valves/etc are all within spec and doing their job sealing their 
various surfaces, there should be no positive pressure in the valve cover/oil 
fill area.  If anything is leaking, then combustion gasses 'blow by' the rings 
and pressurize the valve cover/oil fill area.  That would cause the cardboard to 
'flap' or percolate as you put it. 

Cheers,
Marco
 



________________________________
From: Joe <joe at haasenpfeffer.com>
To: vwdiesel at vwfans.com
Sent: Tue, August 17, 2010 2:37:20 PM
Subject: [Vwdiesel] Blow-by test?

I recently saw a vid on You Tube for a different brand of diesel, and they
were checking the engine for a "blow-by" test.  They pulled off the oil fill
cap and would lay a small piece of cardboard over it.  If it doesn't
"percolate" then it's OK?  What does this mean?  And what is an acceptable
amount of "percolation"?  Because my 82 Rabbit does it quite well.

Oh, I guess "percolate" isn't the right word... Was thinking like an old
coffee pot.  Hopefully you know what I mean?

Joe


_______________________________________________
Vwdiesel mailing list
Vwdiesel at vwfans.com
http://www.audifans.com/mailman/listinfo/vwdiesel