I have a 03 F-350, 7.3L. There is a slow oil leak that only leaks after I've run the truck. In other words, it doesn't just sit and leak overnight. I'll park it after running, and the next morning I'll notice a small pool of oil, approximately 2" in diameter. The leak appears to be coming from the oil pan area. I degreased the entire oil pan area to get a better visual of where the leak is coming from. I can see oil trailing down the front of the oil pan and the rear of the oil pan.

Does this sound like the gasket? Or, what else could it be? I'm praying its not as bad as I think and need to replace the gasket.

Thanks for any input.

Mcnitchell

 

Sounds like a leak from your ICP sensor, HPOP system, or turbo o-ring(s). These systems will leak when under pressure, but not otherwise due to their being in higher positions than your oil pan. When they leak, they leak into the engine valley and then out of the valley through a drain hole in the rear passenger side of the valley, and then down through the inspection cover on front of your transmission and out through an eye-shaped drain opening at the bottom edge of the cover. When running the truck, the air turbulence can cause the oil leak to move around a bit.

Another culprit might be your oil cooler which is mounted on the driver side of the engine directly underneath the exhaust manifold. It has o-rings which are known to fail and you can get either oil leaking outside or from inside the cooler into your coolant system, depending upon which o-ring is leaking. I know one FTE member who experienced his oil cooler leak actually getting blown up and into the valley, only to end up draining out on the passenger side through the same valley drain path described above.

One last culprit could be either the oil pan gasket or the o-ring or gasket at the flange where the dip stick tube enters the side of the oil pan on the passenger side.

All of the above are known leak potentials, especially on our aging trucks. There are tons of write-ups on fixing all of them here within FTE, so you're in the right place.

Get a flash light and a mirror on a stick. Run the engine and look around carefully with the engine running (and warmed up completely). Have someone in the driver seat periodically punch the accelerator to provide short bursts of oil pressure. If you are only getting a 2" diameter puddle from overnight, it might be too early in the process of gasket or o-ring failure to actually see the leakage.

in the meantime, keep a close eye on your oil level in the sump because you are actually losing more oil than you know while the engine is running. That little 2" puddle might make it look minor, but that is only occurring while the system is letting off its pressure with the engine down.

 

I looked in the valley directly behind the turbo pedestal. I didn't see any pooling oil there. I'll take a look around like you said. Thanks!

 

If it's not showing in the valley, it points to either oil cooler, oil pan gasket, or oil dipstick flange gasket/o-ring.