i have a 1996 mitsubishi 3000gt. the exhaust smokes only when im driving. i was just in the driveway getting the engine hot and no smoke at all. so i went for a test drive and 1000 feet later, the starts smoking and smeels like burning from the exhaust.
You have a broken head gasket. While ideaing, theres very minimal friction and presure, however, once you drive it, your adding more of both, causing small amounts of oil to be forced through it, leaking into the exhaust manifold which in turn burns the oil and producing the smoke you see, plus, the buring smell.