I have a 99 E350 7.3 and noticed a quarter size black stain on my driveway where the little opening in the torque convertor cover is.

Anyone happen to know what this might be due from?

Thanks.

 

It might be from a transmission front seal leak. It might be an engine oil leak that ran down the back of the engine. It could be a rear main seal leak.

 

Take a flash light and shine it into the valley under the turbo. If the high pressure oil pump (located over the front of the valley) starts leaking, the oil drains into a hole in the rear of the valley that empties into the bell housing and then out the hole you mention. There's an oil passage to the turbo that's sealed with an O ring under the turbocharger too, that could be the source of the oil as well.

 

Thanks guys. Not a wrencher so I will have to study up on the parts you guys mentioned and try to trace what you guys said. Will try to maybe take some pics. If im not mistaken, the areas you guys are talking about is when I take off the doghouse cover?

 

Yea, you'd need to pull the cover to see into the valley. The turbo is on top of the engine at the rear. Or at least it is on the pickups.

 

Don't panic......It's almost always NOT a Trans. or engine seal leak and almost ALWAYS something on top of the engine running down the valley and through the drip hole! USUALLY, Most common culprit is the HPOP lines/seals. It's just a PITA on vans to get at this stuff AND do the cleaning needed to find the leak area for sure. An HPOP line drip gets blown all over the place and makes a mess and it's hard to see it's the HPOP line until you do a clean job. Ask me how I know!
You need to make or buy a special tool to remove the lines. Someone here I am sure can tell you the specs. on how to make it. I will guess and say you use a 9/16ths wrench that you grind down thin and bend & shape. I forget. ALSO.....Don't remove anything from the HPOP (ICP control) or other "plugs" unless you are SURE what they are! There is one plug that if you remove it you CANNOT just reinstall it with the HPOP installed in the vehicle! You must remove the whole HPOP (much bigger job). It's something to do with a small steel ball that falls out of position when you remove this specific plug (with a stem on it) and to reinstall it you must place the HPOP in a specific position (on a bench). So just make sure you have identified all the stuff before you start R&R ing seals.