I've started to notice this recently but can't figure out what the problem is. For much longer before this smell, I've notice some oil on the top of the engine cover as if it were coming out of the oil cap. I replaced the oil cap (assuming it was the gasket) but that didn't solve it. What could it be? Warped head? Head gasket? I (supposedly) had the head gasket replaced by my mechanic. Also, I've noticed a mild whining sound now that it's cold. The sound correlates to the engine RPM but not to any specific gear. The sound seems to fade away after the car has been driven and warmed up for about thirty minutes in the morning. What might be causing this sound?