The smog technician will have to identify your vehicle as having a modified PCV (positive crankcase ventilation) system. I'm taking my car up for a 70 mile drive today so hopefully everything will get cleaned out. Unfortunately, installing an oil catch can will cause your vehicle to fail the smog inspection. I only have a 3 mile commute to work, which I guess is a blessing and a curse. This will eventually begin to create varnish like deposits from the high concentration of combustion byproducts remaining in the block. There will only be a pressure relief from all the blow by gasses. There will be no "purge" air entering the block. Running an open line or a catch can will prevent pressure from building up in the block but the down side is that there is no active ventilation. After numerous short hot/cold cycles the condensation begins to build up and you can actually see it under the oil cap as a muddy looking foam. Without the proper ventilation it takes much longer to dry out the moisture since the block is no longer actively being purged. cover breather adapter is perfect for installing dash hoses to the catch can. With a properly ventilated block the moisture gets purged out with the incoming air. 7lbs Flywheel For Vw Mk3 Golf Gti Jetta Passat Vr6. The block never gets 'ventilated' and can develop an internal sludge build up, especially if you do a lot of short distance driving. It has two hose adaptors, but one is blocked. When you pull off all that "stuff" the block can no longer actively expel bypass gasses entering the block from the combustion process (piston blow by, leaking valve guide seals etc). I just bought a catch can from ebay and the theory isnt difficult, (ie cut the host between PCV and intake and run them to the catch can) but the bits that come with it dont seem to lend themselves to that. During steady state cruising the PRV actually draws fresh air into the block and out through the manifold.
There is one function of the PRV / PCV combination that is often overlooked. Yea after searching for a while then posting, I stumbled across this thread: