From: aeporro@ariel.lerc.nasa.gov (Bob Porro)
Subject: Re: Oil in Air Filter
News-Software: VAX/VMS VNEWS 1.41    
Organization: NASA Lewis Research Center
Distribution: na
Date: 30 Sep 1992 08:12 EST  

In article <1992Sep26.190246.1417@wuecl.wustl.edu>, christos@wucs1.wustl.edu (Christos Papadopoulos) writes...
>In article <BuL8p9.CBy@cs.dal.ca> gajewski@ug.cs.dal.ca (Andy) writes:
>>Hi there,
>>	One sunny day I cleaned my engine and decided to take a peak into the
>>air filter. It was replaced about 3 months ago. When I opened it up, the filter
>>was black. On the bottom of the filter box, was a thin layer of oil. I cleaned
>>it all out, and then inspected the top cover. It seems that the oil was
>>dripping down from the cover on to the air filter. On top of the cover is all
>>those silver fuel lines and the fuel injection system (I think).
>>
>>	Anyway, it is an '85 GTI and has 128K on it. It driven very hard
>>and the rev limiter gets activated about once a week. Just recently I pulled
>>out pin 11 from the computer and I have a slight nock. The ignition timing
>>will be checked tomorrow in order to fix the knock. The oil if fine and the
>>coolant level was just below the min mark. It is now filled up.
>>
>>	I think that the oil got in through the air intakes when the rev
>>limiter kicks in. Can anyone confirm this? Or if it is something else could
>>you please let me know and a suggestion on fixing it.
>>
>>	Thank you in advance,
>>	ANdy
>>-- 
> 
>	I have a similar "problem" in my 84 GLI, athough it is not as severe
>as Andy's. My air filter simply had a stain of oil, but I never hit redline
>when I drive. Is this something we should worry about? Please help!
> 
>Christos.
> 

This is a common problem with the VW 4 cylinder engines as they get older.
If you look carefully, you will see a hose running from the top of your 
valve cover to the air filter box.  I believe this is the positive crankcase 
ventilation (PCV) line.  Most auto companies install a check valve to 
keep oil from flowing out of the engine, but VW does not.  Instead VW valve 
covers have a filter system permanently mounted in the valve cover itself that 
is supposed to keep the oil from escaping out of the valve cover.  It appears 
to me that after a period of time (years) this filter gets saturated with oil 
and becomes ineffective, so oil starts escaping via this line and deposits 
into the air filter box.  Part of the problem may be attributed to the fact
that as engines get older, they tend to build up more pressure in the head
which allows more flow through the PCV hose. VW tried to fix this problem by
installing a splash guard that sits on top of the cam bearings in 1985 and
later vehicles, but it hasn't been totally effective. 

As for the solution of this problem, I don't know.  I would install one of 
these splash guards and maybe get a new valve cover.  

******************************************************************************
| Bob Porro                    || (The opinions expressed here are not       |
| aeporro@venus.lerc.nasa.gov  ||  necessarily those of the management ?\*!) |
|                              ||                                            |
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