I have read much of the archives regarding this
topic, but I am still stumped.
I have a 1994 850 wagon 2.4 NA that has what
I feel is excessive crankcase pressure. If you pull
the dipstick while the engine is running you will
hear a release of what I would guess to be 5-10 psi.

Here is what I have done to this point.
Replaced Oil disptick seal
Oil filler cap seal
Removed Intake manifold
Replaced Oil separator
Cleaned/replace all Oil separator
hoses
New flame trap and housing
Replaced small vacuum line to flame trap
Cleaned throttle body/EGR

Upon removal of the old oil separator
I did note some blockage in the pipes
going into the separator. I was hoping that
was the problem, but when I put everything
back together the problem still exists.
I am concerned that I am going to blow my
other oil seals (main, front, cams, etc.) if I
continue to run the car with this problem.
Since I have replaced the filler and dipstick
seals there are no longer any oil leaks, but
maybe that was a good place for the pressure
to be going?

Any input would be greatly appreciated.
--
1990 240DL - 201K, 1994 850 Wagon - 161K, 1989 Ranger 238K

How is your oil usage, and is there oil in the exhaust? Eventually an engine will wear so much that there is more blowby than any crankcase vent system can handle. Hope you are not yet to that point.

Oil usage is about 1/2 quart per 1,200 miles.
The tailpipe shows evidence of oily exhaust,
but you can never visibly see it burn oil (blue)

I was wondering if the piston rings are wearing
out, I guess at 161K it is a possibility. I guess
I need to do a compression check and see where
that takes me.
--
1990 240DL - 201K, 1994 850 Wagon - 161K, 1989 Ranger 238K

The line that runs from the bottom of the air-intake hose (the large, maybe 3 inch diameter hose from the air box) to the throttle body has a bayonet connector on it that often gets clogged. It is from here that the line runs to the oil separator. Use a pipe cleaner...one of thse with the brissles dipped in alcohol to clean out the connector part really well. I did the same pcv hose and related item replacment and still had a "clogged" system until I cleaned that connector out. Also, in your case make sure the flame trap is clean. You might consider throwing away the flame trap all together and just having an empty flame trap holder in your lines. Either way, attempting to tighten down your dip-stick with better vacuum, etc. will surely cause a blow-out somewhere else if you have excessive crankcase pressure, so I wouldn't worry about getting a good seal there. Good luck!
--
1998 S70 T5 Emarald Green Metallic, 2004 V70 2.5T Ruby Red, Previous Owner of Black '94 850 Turbo Wagon. My cars have been running so well lately they've got me worried.

Thanks for the advice
I replaced the flame trap and flame
trap housing that goes into the air
hose you speak of, as well as adding
a new small vacuum line to the
flam trap housing to the vacuum "tree"

I have not tried removing the flame
trap yet - that may be the next step.
--
1990 240DL - 201K, 1994 850 Wagon - 161K, 1989 Ranger 238K

Fixed - for now.

I started taking it apart again this
evening to see what is going on.
My 5 day-old flame trap and housing
was full of solid black crud that was
blocking any air flow, the small
vacuum line was completely blocked
as well.

I found it hard to believe as I had just
replaced the oil separator and cleaned/
replaced all of the related lines and
hoses. My only guess is when
I replaced the parts, crankcase ventilation
started blowing at a much higher flow
than before - freeing a bunch of crud out
of the block passages that I could not
reach. I am glad that the flame trap was
there, otherwise all of that crud would have
gone right into the intake. I will be watching
that flame trap like a hawk these next couple
of days/weeks. Hopefully that's all that will
come out. Lesson learned.
--
1990 240DL - 201K, 1994 850 Wagon - 161K, 1989 Ranger 238K