oil filler breather

[etlsport]

Lately my VX has started burning oil a whole lot faster than it used to.. probably about 1 quart every 1000 miles now. making me kinda nervous..

at a car show the other day I saw a grand prix with a breather filter on his oil filler. I know some VX owners have done this on their PCV. any harm in giving them both a try? I know some oil pressure is a good thing, will the filter stop pressure buildup? any thoughts would be appreciated

[Y33TREKker]

With a breather filter in place of your PCV valve, you wouldn't be decreasing your actual oil pressure. What you're doing is reducing air pressure in your oil pan (crankcase). Oil pressure is created by the engines oil pump.

The PCV valve moves any excess air pressure in your oil pan (generally caused by piston ring blow-by) to your intake so the gases can be burnt and expelled in the combustion process. When you put a breather filter in place of the PCV valve, all you are doing is venting any excess crankcase pressure/gases out of your engine. The reason a filter is used is because sometimes those excess gases can contain oil particles, so the breather filter catches those in the filter element.

I don't recall exactly when I replaced my PCV for a breather filter (would have to look at my records), but I've not lost any oil since, so I for one can say it wouldn't hurt to give it a try. (I should say I wasn't losing any oil before the swap either, so I just considered it preventative maintenance).

[Ascinder]

but I've not lost any oil since, so I for one can say it wouldn't hurt to give it a try. (I should say I wasn't losing any oil before the swap either, so I just considered it preventative maintenance).

X2 to that for me. Plus them you never have to worry about the pcv locking up. The breather is covered up by the plastic engine cover too so you don't need to worry about any inspectors catching it.

[VX KAT]

Trying to understand this better...and just changed my PCV this am, in prep for my trip.....if the PCV locks up...what's the series of events that will take place and how or when does oil loss come into the picture?

Any telltale signs to look for when a PCV locksup?

OK, this may be a really stupid question....If the PCV should freeze up along the way (and I'm carrying a spare of course), is it possible to just remove it and leave it out of the equation, and somehow cover the port and the tube with something breathable? (I'm kinda thinking of how a breather filter is set up, and thought a breathable cover might work OK as a quick fix).

[Ascinder]

if the PCV locks up...what's the series of events that will take place and how or when does oil loss come into the picture?

IIRC when the PCV locks up there's a suction created and the engine begins to devour oil. There's plenty of threads on it. I think that Psychos2 had some stuff to say about it and had been running a breather for just that reason.


Any telltale signs to look for when a PCV locksup?

Burning oil? More than normal? I don't know, mines been gone awhile now.


OK, this may be a really stupid question....If the PCV should freeze up along the way (and I'm carrying a spare of course), is it possible to just remove it and leave it out of the equation, and somehow cover the port and the tube with something breathable? (I'm kinda thinking of how a breather filter is set up, and thought a breathable cover might work OK as a quick fix).

I would think that would work.

[Y33TREKker]

OK, this may be a really stupid question....If the PCV should freeze up along the way (and I'm carrying a spare of course), is it possible to just remove it and leave it out of the equation, and somehow cover the port and the tube with something breathable? (I'm kinda thinking of how a breather filter is set up, and thought a breathable cover might work OK as a quick fix).
That's essentially what some here on Vxinfo have done. There are other ways to do it I'm sure, but I took an old PCV valve, removed the internal valve (check-ball and seat), bought a small breather filter with an inlet tube the same diameter as the one on the PCV valve, then connected the two with a section of rubber hose.

The gutted PCV valve is then placed back in it's original position in the valve cover, and there's your PCV/breather filter setup. If internal crankcase pressure builds up, it's simply vented out of the engine, and if there's any oily residue in what's being vented, it's caught by the filter element of the breather filter.

A PCV valve is only supposed to allow air to flow at certain times ---> when there is positive crankcase pressure ---> allowing the pressurized air to open the check valve and flow from the crankcase (oil pan area) via various passages up to the cylinder head and valve cover area ---> through the pcv valve and tubing ---> into the intake manifold. If the pcv valve get's stuck open though, the vacuum in the intake manifold will have the potential to suck in oil and oil vapors all the time and is where the oil loss occurs.

Just remember that since you are removing the connection between the pcv valve setup and the intake manifold when you install a breather filter, you also have to cap the port on the intake manifold where the pcv valve tubing went. Otherwise you'll have a vacuum leak.