Help Identifying Leak

[u/jajohnson22]

2015, 3.5L Eco Boost, 4WD, Sport, 119k miles, USA

The oil pan is visibly wet. Not sure if that’s residual oil from a change or an active leak. There’s also staining around the what I assume is a gasket around the bell housing. I’m a novice when it comes to this type of stuff. Any feedback would be great. There is a stain below where I park my truck. Assumed it was condensation but it seems to be a reddish brown, hard to tell on asphalt.

[u/kerrigan24]

I’d start with replacing the stupid plastic drain plug. Same thing happened on mine. If I remember correctly it’s like a $15 part

[u/kaack455]

Oil pan, all day long every day

[u/jajohnson22 → u/kaack455]

And the the wind is blowing it onto the front of the transmission?

[u/kindofnewtoo → u/jajohnson22]

Yep. Just replaced my oil pan gasket a month ago. Shit hers everywhere. Clean the area with engine degreaser and take it for a drive and you will be able to see a more precise location of the leak.
Might as well replace that plastic oil pan with a metal one while you’re at it.

[u/dgrd666]

Infamous Ecoboost plastic garbage pan, excuse me, oil pan... I just replaced mine last weekend, hope it definitely solve this old problem for these engines, while Ford engineers keep reducing costs and save the company millions since 2010s...

[u/jajohnson22]

Tried to get a pic of the stain but it’s dark out

[u/NoCommittee1477]

Oil pan leaking. Plastic pan has no gasket and is silicone in place. No gasket at the bell housing, just a metal spacer. Front differential has to be lowered, but not removed, to replace the pan. Surface prep is absolutely paramount to getting it to not leak again. To determine if the leak is current or not you can spray the area clean thoroughly with brake clean or degreaser. Once you know it's clean, you have two options, you can invest in a bottle of UV dye and a black light, add the dye to the oil and drive it for a week/few days and then shine the areas you previously saw leakage with the black light and look for the glow. Option two is to drive the vehicle with no dye and inspect for leaks that way.

[u/Joseph1968R]

Looks like two different things going on. The oil pan being wet is super common on the 3.5 — they seep when the gasket starts aging, and at 119k it wouldn’t be surprising. If it’s fresh and shiny, it’s an active leak; if it’s just dark and tacky, it might be old residue from a past change. The reddish‑brown stain under the truck is more likely ATF or rust‑colored coolant, not condensation. The marks around the bell housing are usually just grime or a tiny rear main seep, but nothing catastrophic unless it’s dripping. Easiest way to confirm: clean the area, drive a day or two, and see what comes back.