I have a 1999 F150 5.4, 130k miles. Starting to leak down the exhaust, starter, and then off of pan. Not sure where leak is coming from. Looking from the top side engine bay and can't see anything leaking besides a little wet in the valley closest to front of truck. Also have pieces of black plastic broken under intake in valley as well. Pull pieces out and they easily break like they have been worn from heat. Also truck has been having issues starting lately. Takes a couple extra cranks each time to fire. Not sure if that has anything to do with it though. Thinking head gasket but unsure. Positive it is oil and not coolant as have to add oil quite often. Thanks for any help.

 

A little confused, so leaking on the manifold , front or back? Or on the flange connecting the cat?

If your pulling hard rubber/plastic out I'd say it is the bottom of a worn valve cover gasket that's hardened and leaking oil down on exhaust manifold.

Have any pictures of the leaky area and where the hard rubber/plastic came from?

 

Not leaking on manifold. Only way I can see the leak is crawling under truck just behind front passenger tire. Leaks down where exhaust turns to go to rear of truck and all around rear main seal before it hits ground. Can try to get pictures tomorrow to see if that helps.

 

Chasing a leak on the boys' F150 as well. No leaks up top. But on the bottom it looks like what you describe. Wife's truck is on the ramps in the my garage ahead of it. When there is time and space for the F150, first place I am going to be looking is the oil filter adapter flange. We recently fixed a leaking power steering pump hose in that area. I suspect that perhaps there was/is actually both leaks going on at that location, the PS and the oil filter adapter gasket. Hope this gives you an idea of one "common" place to look for leaks on the 5.4
Let me know if thats the issue on yours?


... the plastic pieces and hard starting, I am going to suggest are completely separate issues unrelating to the oil leak.

 

I had the dreaded Oil Filter Housing leak that I fixed. Make sure you have a long Extension if you have a 4x4. There is not allot of room with the Differential between you and the housing.

It did not make the Truck hard to start. The truck just liked to mark its territory every where it went. =) And yes it looked like it was leaking at the Rear main seal, but it was just wind blown from the Oil Filter housing.

 

Only got a picture of the top side tonight. The broken pieces are laying in the gap just behind and to the left of the alternator. If I shine a light down in there I can see them. Same with the other side of intake. Thanks everyone for the input so far.