I recently bought a 2005 f150 STX 4.6L and overall it's in pretty good shape other than an oil leak that needs addressed. I have a few questions, any help would be appreciated. (I'm not a big vehicle whiz but I'm not hopeless either.)

The oil covers the bell housing and a small amount collects on the ground. I know it very well could be a rear main. Is there anything else it could be?

Also there's a spot under the hood where it appears to be oil collecting. Any ideas on it?

Last question, (this will sound dumbest of all) is this the correct dipstick? The reason I ask is that all of the replacement sticks I have seen are straight and this one is twisted and seems to be very awkward fitting in and coming out when I check the oil. According to this, the oil reads on the low side. Previous owner said he had an oil change not long ago (within 500-1000 miles if I remember correctly)

 

 

Not sure the mileage on your truck but I will say that the underside photos you show remind me an awful lot of the oil leaks that have developed over the years on our old '05 Escape. I do my own oil changes on the vehicle every 3000 miles and have never found the vehicle to actually run low on oil over that many miles despite the leaks. I guess what I'm trying to say is that as a vehicle gets older, I'm not sure there is a ton of wisdom in replacing gaskets and seals to address the leaks unless you are seeing a noticeable drop in the oil level and/or if the leaks simply drive you nuts! I see this more as a natural and unavoidable occurrence as a vehicle gets up around the 150,000 mile mark and kind of feel you get to the point where you just accept them as part of the "charm" that goes along with running a higher mileage rig.....

 

The valve cover looks to be leaking around the filler neck extension. I'm not sure on the 4.6, but on the 5.4 it twists into the VC and has a seal on it. You might be able to fix that by removing the filler, cleaning it, and augmenting the seal with RTV. The lower leak is either the rear main seal or oil pan. You could check the torque on the oil pan bolts. If that doesn't fix it, you'll have to decide if you want to install a new seal.

 

It's at about 90,600 miles. I topped off the oil and have been driving it. It seems to leak the same amount every time it's parked. It doesn't appear to continue to leak after the initial amount. I put a paper bag under it to get an idea of how much it was. I'll try righting the oil pan today and see if that doesn't help. The body is in great shape so I'd like to maintain it even if it means putting a little work into it. Does anyone have any idea what a rear main replacement would cost on it?

 

Pretty Truck!

I'd take some wrags and see if I couldn't clean up underneath and maybe establish what it is that is leaking. I agree the oil spout likely could be sealed with a new seal ..... and I'ld try a new PCV as well. I'd also pull that plug and look up inside the bell housing area. It does look like a rear main seal.

Dip stick looks correct to me.

 

Rear main seal won't put oil on the valve cover. I'd start there and clean everything up to see if that fixes it.

 

Could be just a filler tube seal .... but sure looks like an awful lot of oil on the pan / bell housing for a oil filler tube seal. Could be PO was just really sloppy when refilling after oil changes and didn't care to clean up, maybe he just didn't have a step to use to reach it?

Also, might be worth looking at the gasket area between the lower rad hose / filter mount casting and engine block. I had a bad leak start there on a '95 4.6.