This problem is not with my F-150 it is with my 2000 Nissan frontier V6 so Please forgive me.

I have been smelling the oder of burning oil not smoking or anything just the odor. I checked the oil level and it is with in normal ranges. I then looked over the engine and found a Little line of oil running down the header shield just below the oil fill but I haven't put oil in this truck for a while.

Today I when I got home from work and the truck still very warm i used break cleaner and cleaned all the oil from the side of the engine and heat shield. I then saw a very little trickle of oil come from under he valve cover. I went in the house and got a Phillip head screw driver and turned the screw that was close to the oil line and it turned in about 2 full turns. I then checked the rest of the screws and they all where loose by 1 to 2 full turns. I then rechecked the oil level and ti is still fine. I then took it out for a drive and it was like the truck had more power and quicker response. I drove it for a while and didn't notice any oil smell.

Could the loose cover been a cause for power loss and the very light oil leak?

What should I torque the screws to? I just got them as tight as i could with a small screw driver.

Is this a comon issue?

 

Your repair, which might be only temporary, could take care of the oil leak and odor. Cannot understand why there was a benefit in engine performance, this is strange to me.