Brand new 5.0 lariat main engine seal leak

[TjCanuck]

Just purchased a brand new 2025 F150 Lariat 502A 5.0L coyote last week. Once I got home I found oil leaking from the rear of the engine and the front stabilizer bar was coated in oil.

Took it back to the dealer yesterday and they found the main engine seal leaking. This truck has 200km (125 miles) on it and I’m at a loss for words. I switched from a 2017 3.5 ecoboost gen 2 to the V8 for engine longevity (I know the V8’s are still pretty complex engines. The irony is palpable.

I have seen a few other posts on here about extremely low mileage main engine seal failure. In one case it leaked multiple times but that was due to damage during reinstallation which eventually resulted in an engine replacement.

For those that have experienced this failure at low mileage have you had success with a one time repair or am I in for a world of perpetual issues with this truck?

Maybe this is my karma for saying I would never buy a Ram because it would break down before I left the dealership lot…

Nov 5 2025 edit: Main seal was replaced. Engine leaked again after test driving. Dealer is installing a new engine.....

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[Porpoise Hork]

Ford has had issues with the rear main seal on the 5.0's. Have not seen many reports of leaks from the front like this. Could just be a bad seal on the timing belt cover.

From what I have seen Ford has just been replacing the engines with this issue instead of replacing the seal.

 

[Jerome10]

My suspicion would be they’ll fix it.

This, unfortunately, is the type of thing I have felt for years Ford needs to pay more attention to… actual assembly quality.

For the most part I think the engineering is solid but they have struggled a long time with actually putting it together well.

My 2023, from the factory, had a quarter-sized paint bubble right in the middle of the bed. It has some dirt under the paint in a couple spots. A hose clamp from the air filter box to engine was installed but not tightened. An active grill shutter was snapped off and hanging. All beyond unacceptable on a brand new vehicle from any brand. It just makes you hope they didn’t forget stuff you can’t see or tighten yourself.

I’d probably let them fix and not worry about it. Chances are they’ll get it right and you’ll be good to go.

 

[264winmag]

Ford has had issues with the rear main seal on the 5.0's. Have not seen many reports of leaks from the front like this. Could just be a bad seal on the timing belt cover.

That is the rear of the engine not the front seal.

 

[Porpoise Hork]

That is the rear of the engine not the front seal.

My mistake. Coffee hadn't kicked in yet. lol

 

[JExpedition07]

They have had a handful of these over the years on here, it seems like on assembly they damage the rear main on some. One guy they put in a scored up crankshaft that was likely dropped at the factory and it ripped up the seal. Ford quality. They will fix it as the motor is fine.

The 10R80 in the brand new Transit I bought this July is clunking and has a huge delay going in and out of gear. My third 10R80, not happy with one of them. All clunky piles of crap.

 

[Porpoise Hork]

They have had a handful of these over the years on here, it seems like on assembly they damage the rear main on some. One guy they put in a scored up crankshaft that was likely dropped at the factory and it ripped up the seal. Ford quality. They will fix it as the motor is fine.

The 10R80 in the brand new Transit I bought this July is clunking and has a huge delay going in and out of gear. My third 10R80, not happy with one of them. All clunky piles of crap.

Bean counters to the rescue forcing them to use sub-standard parts in the valve body. Why build it to last forever when you can save a few bucks per truck and just build it to last 100K miles.

Possibly.

 

[TjCanuck]

They have had a handful of these over the years on here, it seems like on assembly they damage the rear main on some. One guy they put in a scored up crankshaft that was likely dropped at the factory and it ripped up the seal. Ford quality. They will fix it as the motor is fine.

The 10R80 in the brand new Transit I bought this July is clunking and has a huge delay going in and out of gear. My third 10R80, not happy with one of them. All clunky piles of crap.

I have always had good luck with the 10R80 lottery, even in rentals/loaners.

I had a couple hard shift issues with my ‘17 over the years, usually around 4th-6th gears. It was fixed both times by resetting the adaptives and drove like new afterwards

 

[sporkfed]

Probably Cheeto fingers when installing. Which factory are the Lariats assembled at?

 

[TjCanuck]

Probably Cheeto fingers when installing. Which factory are the Lariats assembled at?

Deerborn

 

[sporkfed]

Deerborn

In that case, kebob fingers.

My Kansas City truck has been flawless, other than having a weak 12V battery, but I believe that's either by design or my fault.

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