Hey out there .. i have a 1998 Cavalier with i believe the 2200 2.2L, i noticed tonight my valve cover on top has a crack in it around where you tighten it up on one spot and there's a little bit of oiling that's getting out, this is on front of the valve drivers left side, it's now running lean to went from 500km's city to 320km's maybe, on a Full Tank, Guess the engine valve crack is sucking in Extra air there to make the car now run lean? ne hows though, I was wondering how much you guy's think.. taking the valve cover off and getting it fixed would cost at a proper shop? or getting a new one with a new head gasket will cost me? but yeah cavy run's great for a couple minutes then start idling bad & rough acceleration, turn the car off, restart right away and it runs good for another couple minutes, any thought's would be appreciated as well, thank's guy's.