The PCV system helps remove extra pressure built up in the valve cover and in the crankcase.
The valve cover can become pressurized by either the valve seals leaking or the one-way valve leaking and letting in boost from the throttle body.
The crankcase becomes pressurized when the boosted air slips by the piston rings.
The bad news is that the first generation PCV system did not handle the crankcase pressure very well.
This caused the oil to get contaminated very quickly and then it would sludge up much easier. This is
why SAAB recommended short oil change intervals and high quality synthetic oil.
SAAB has gone through six generations of the PCV system. The final design
seems to work without any oil loss and helps reduce the crankcase pressure that
causes oil sludge. It's only $75 for the new PCV system and the two additional
hoses and takes about an hour to install.
If you just bought a used 9-5 and you do not know the condition of your engine, then you should make sure your car has the latest PCV
system and check your engine for sludge. The fastest way is to take off the valve cover and take a quick look.
If things look pretty good, then your oil pan is probably okay as well.
I also have a DIY procedure for dropping the oil pan.
Drop Oil Pan
For more information on the sludge problem, check out this SAAB dealer's website.
Andrews of Princeton
You need to buy the following parts for this job: