if the car has an ass load of miles on it then its just buring oil...if you have to add 1 quart ever 1.5 months then that dosent seem like a leak sounds like just oil being burned off. if the car dont have alot of miles then it prolly is a leak. i would pressure wash the engine till all the oil is off it then drive until you notice oil somewhere on the engine then jz take it fromt there