My car has a crankcase evac system which basically consists of a tube running from each valve cover to the exhaust to pull vaccuum out of the crankcase and help pull the pistons down. Yesterday at the track at around the 1000 foot mark the car started smoking blueish smoke out of the exhaust like crazy. Once I pulled over and looked it was still smoking badly, but there were no leaks under the hood. Once I got home compression test was fine, no oil and coolant mixing, and no visible leak so I figured the headgaskets were fine.

The car had a little too much oil in it ( 1qt over I think ), so I'm now thinking once the exhaust picked up enough velocity it started suck out excess oil through the evac hoses? Is that a possibility? Once I got home and let the car run, it stopped smoking shortly after ... I'm assuming it was just burning off anything else that was still in the exhaust at that point. What keeps the evac system from pulling oil out even? The fittings that go on the valve cover look like they may help filter, but I still found traces of oil on the tube side of these. Do these eventually go bad and need to be replaced?

 

the extra quart of oil caused so much windage inside the engine that the evac sucked it out. even without the evac say just normal open breather you would have had oil puking out of them as well. with a extra quart your crankshaft can actually make contact with the oil and pick it up and fling it everywhere.

 

Thank you, that's exactly what I was thinking as well. Looks like I'll have to put in the proper amount, and at that point mark the stick so in the future I'll be able to accurately check the level. Thanks!