crankcase venting and oil burning was [Vwdiesel] turbo 1.6 or non turbo advice

[Bart Wineland]

Well guys thanks for helping me understand the crankcase venting and vacuum 
pumps. I did as Roger and Chuck suggested, checking that the vc vent was 
clear and I T'ed into the vc vent line from the crankcase and vented them 
together. I had a newer rotary style vacuum pump from my original '89 
engine that is junk so I replaced the old diaphragm pump with it as Chuck 
suggested.  I also made sure that there are no vacuum leaks. I test drove 
it on a 40 mile run to get some canoe seats and it is still smoking and 
stinking pretty bad. Those were great leads and cost me $4 to try. I think 
this venting method makes more sense so it was a great place to start. I 
have a compression gauge coming any day and will forward the results when I 
get them since I will need help interpreting them. Hagar and Loren have 
also made a couple suggestions and need more info so I will reply to 
hagar's message with some more details.

Thanks again

At 10:23 AM 7/9/2004 -0700, you wrote:
>Bart Wineland wrote:
> >
> > Well I went out and checked as soon as I read this to be sure. My engine is
> > from '86 but has a  older vacuum pump. It does vent back to the crankcase.
> >  From the top of the pump is the vacuum line to the brake boost, a small
> > yellow plastic line that heads for the dash for climate controls and has a
> > third small hose that is hanging free.  I thought the third hose was
> > plugged off but when I look at the "plug" it actually has a very small hole
> > in the center? After looking at the set up I have to admit I don't
> > understand how it all works.
>
>I would make sure that the plug is intact, should not have a hole in it.
>
> > Wouldn't the output of the vacuum pump
> > pressurize the crankcase?
>
>No, pressure out of the pump is probably no more that atmospheric.  It
>can only grab air from the low pressure (vacuum) side and push that out
>the other side.
>
> > How could that ever be good? Are you saying I
> > could pull this line off the bottom of the vacuum pump and just tie it up
> > to vent the crankcase to see if it helps my oil eating?
>
>On my '81/LX pickup, the outlet of the vacuum pump went to the block.  I
>re-plumbed that to add a pair of tee fittings to get the block vent up
>to the valve cover vent.  I wanted to retain the stock plumbing.  If
>your pump doesn't hook up to the block, leave it alone. I think that
>having the pump connected to the block is not a good idea anyway.  Oil
>mist from the block gets into the pump and rots the diaphram.  Also, if
>you have any block pressure/blowby, that can damage the pump.  By
>venting the block to the valve cover vent, you keep pressure from
>building up anywhere in the system.  It worked well on my '81, but my
>main concern was keeping pressure/oil out of the vacuum pump.  If I did
>it again, I would probably do like I have on my '82 (1.9D w/ rotary
>pump) and just have the block-valve_cover-intake vent like I do now.
>
>--
>    Roger
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