Well, I guess my crankcase was creating some incredible pressure and causing a very embarassing, giant cloud of smoke at 60 mph and upwards, so I bypassed the PCV valve and vented the crankcase to a home made oil catch can. Now all my problems are solved. The car was running so good despite the low compression readings (135, 160, 160 in respective cylinders 1,2,and 3) so I thought I'd hold off on doing a JDM swap. I made an oil catch can to vent the crankcase using a water filter assembly I bought from Lowe's, 3 feet of 3/4" fuel hose, and two 3/4" barbed fittings, and an 8" corner bracket. I painted the white filter housing silver to look better in the engine compartment and secured it using the angle bracket to one of the strut nuts. Please see pics below. I also installed a really cool Edelbrock air cleaner assembly after reading about it on Teamswift.net. I had to cut a piece of aluminum to allow the 5 1/8" air cleaner base to fit over the 4 and some change inch, throttle body. The car actually seems to be a lot peppier and sounds a lot meaner. I hope this set up gives me even better fuel economy.
http://s102.photobucket.com/albums/m120/maniacalmetro/

you are a metro maniac in true sense :))

I had a jeep that did the same thing,I put a oil filler breathing cap on it! problem solved!! mybe you can find one or make one. no more oil catcher to empty.your engine is possibly getting blow-by from the piston rings. good luck! dave-2gooses

Thanks for the great advice. I actually thought about it, but it seems like the blow by is so bad to cause so much smoke to billow out the tail pipe. The first time I tried venting the crankcase, I used a hose that barely fit into an empty Valvoline oil can, and at idle, the oil can started ballooning, I had to pull the hose out to relieve the pressure. I'll try to use a breather filter, a large one and see if it works, since they only cost $11.

There is one problem with your breather. You need to hook the other end back into the air intake. A PCV helps the piston rings seal by using vacuum from the motor to make the engine block a low pressure area. At atmospheric pressure, it only vents when there's blow-by. If you hook the other side of the breather up to the air intake, it'll run even better, and quite possibly help the piston rings seal better. And then there'll be no real reason to have a catch can. The engine will consume it(as it was designed to do).

Geo,

I am afraid of routing the other end back into the intake due to the embarassing smoke cloud. This catch can seems to have cured the problem. The little fitting by the battery seems to be completely dry, so I'm wondering if its just venting the fumes into atmosphere. The car runs incredibly well as is, that is why I'm doing the catch can thing. I know I'll eventually have to do the JDM swap, but at the moment its not economically viable. I just reread your post and think I will try it, especially if it helps the rings seal better.

Blowby doesn't cause smoke out your exhaust pipe. Oil mist does. If you catch can is separating out the oil and collecting it, then allowing the "dry" gasses into the intake should not cause tailpipe smoke.

I think. :licka:

Ummm, blow by means your piston rings aren't sealing properly... :screwy: So yes, it does cause smoke out of your tail pipe. Oil mist is just what the crank makes when it splashes in the oil pan. A windage tray could stop misting, but a catch can with no PCV valve will just suck it out of the engine.

I have a 90 Geo that has a simular issue. It has blow by but its intermittent. It will run fine and its like someone turned a switch on, and it starts dumping lots of oil into the throttle body. then it smokes like crazy, burns off the oil then runs fine again. I did a compression test, and it was 170, 175, and 196,
1,2,3 respectively... I dont get why it would be an intermittent problem. I am going to make a catch can for it while i try to figure this out. Ideas? I was also wondering, are there oversized rings available for these motors? Any help would be great.

MJMarkham I would conjecture that the oil slowly pools up somewhere, until there's enough for intake vacuum to suck up the puddle. Or it only happens when you go around a corner / hit a bump and the oil spills out of wherever it was pooling up.

Do you notice any relationship to when it blows smoke? At idle, while driving, high RPM, low RPM, accelerating, decelerating, etc?

MJMarkham I would conjecture that the oil slowly pools up somewhere, until there's enough for intake vacuum to suck up the puddle. Or it only happens when you go around a corner / hit a bump and the oil spills out of wherever it was pooling up.

Do you notice any relationship to when it blows smoke? At idle, while driving, high RPM, low RPM, accelerating, decelerating, etc?

I can rull out it pooling up and the turning a corner thing. I had another person in the car reving the engine while I watched it with the breather cover off and no air filter. It had no oil comming from the vent, then I had them engauge the emergency brake and put it in gear and while two footing the car, put it in gear to put a load on the engine. It did fine for a little while then, like a switch being turned on, oil started pumping from the vent into the throttle body. Then it stopped and went back to normal. when I say pumping I mean a lot of oil... I can only figure that it possibly a combo of a sticking valve and a bad head gasket... More input please... Thanks

Sounds like you have the same problem as me, however, your compression numbers are very good, so I'm wondering why its doing this. My car only did it while I was cruising at 55 mph or higher, but around town, idle, and low speed, I never had the "mosquito fogger" problem. I am going to vent the other end of the catch can back into the valve cover to see if it'll cut down on catch can emptying intervals.

Well, I went to the ol' Home Depot and gought some schedule 40 pipe fitting and random other brass fittings and made a collection tank for the oil being pumped into the intake... I will post some pics of the aparatus later, but I did build it to retain the vaccum lint to the breather. all in all it took about two hour total to build and install...