L05 blowing oil into air filter housing...fix?

[CID Vicious]

Got a 92 L05 Caprice wagon, 220k, that's having some kind of positive crankcase pressure issue - I put a new PCV in and it's still pushing oil up into the air filter box near the injectors. The car had some really gunky oil in it that just got changed.

I'm looking at taking this car on a long trip in the next few weeks. I'd like to get the issue sorted out before I leave if I can.

It mostly runs fine. The 'low oil level' (LOL) light comes on pretty frequently even though I check the oil and it's never low.

???

[GoldSSWagon]

I'd do a wet/dry compression test first.

[wytltng]

Make sure you have suction on the pcv hose with engine running. If ok I would say you have bad rings.

[Fred Kiehl]

Originally Posted by CID Vicious

Got a 92 L05 Caprice wagon, 220k, that's having some kind of positive crankcase pressure issue - I put a new PCV in and it's still pushing oil up into the air filter box near the injectors. The car had some really gunky oil in it that just got changed.

I'm looking at taking this car on a long trip in the next few weeks. I'd like to get the issue sorted out before I leave if I can.

It mostly runs fine. The 'low oil level' (LOL) light comes on pretty frequently even though I check the oil and it's never low.

???

Putting a new pcv valve would probably make the situation worse. My first guess is the same as wytlting...bad or broken rings. Does it smoke?

My low oil light is on a lot, and it is probably a bad connection. You could also have a drainback issue on one side of the engine. If the oil level in the head is high, the oil could be sucked into the pcv system (BTW there are 2 pcv valves, one on each bank. If you have a drainback issue, it could also make your low oil light come on, because the oil is staying in the head, instead of the pan.

[CID Vicious]

Well there's just an elbow at the passenger side of the motor. I'm guessing it's supposed to be a PCV also, and I have the one I took off. I never tested it, just replaced it, so that's possibly it.

This thing has dumb 'repairs' all over it, missing sway bar bushings (?), so if someone 'replaced' a PCV with a plain old elbow I'd be less than surprised.

The car makes good power for what it is so I'd be surprised if I had rings going, and it doesn't smoke.

I'll throw the old PCV in the passenger side bank and put the new filter in, and see how dirty it gets.

[Fred Kiehl]

If it continues to suck oil, You should pull the valve cover, and check for oil drainage issues. The engine will suck a little oil through the passenger's side vent, into the intake plenum chamber. It is a strange setup.

My passenger's side valve cover looked like it had just an elbow, but when I pulled on it, it turned out to be a PCV valve.

[waynes91]

had a problem with the tube on the tbi was plugged up,had to use a drill to clean it out (was able to turn drill by hand) been no problems after that

[sprocket]

I had the same issue on my 1973 Poncho Gran Ville w/455.
My air filter would actually drip oil it got so wet. Pulled the valve covers and poked the return holes with a coat hanger. It helped some, but I sold the car two weeks later (needed tires, a new vert top, etc etc) so not really sure how well it worked. they were clogged pretty badly, engine was super dirty in there....

[convert2diesel]

Before ripping the engine apart, check three things.

1. The PCV port in the throttle body tends to carbon up in these engines. You still get some vacuum but not enough flow. You may have to remove the throttle body to get it really clean.

2. Pull the valve covers and check the oil return ports. Had 91 with same issue and found the return ports plugged solid with gunk. Cleaned out the ports and problem solved.

3. Replace PCV just on spec. Get one from the dealer. Their cheap and I have had a few bad ones right out of the box when buying aftermarket ones.

Only after checking these things would I start going deeper. For the price of a few gaskets its also good insurance. All of these things happen over time so its not a question of if, but rather a question of when.

Bill

[Allan H.]

The way the system is designed it supposed to pull any vapors the PCV system can't handle, like excessive blow-by from wear, back through the passenger's side vent tube and then into the air cleaner.
There can't be a PCV valve in the passenger side valve cover or the system wouldn't work right? That's the PCV air intake and it would build up vac inside the engine and start sucking oil and air from anywhere it could.
Blowing through A PCV valve outlet should close it up on a good valve and that is the flow direction needed for the air being pulled into the engine for the system.