I bought a used 96 F250 5.8L. When it sat overnight, I notice a hand-sized oil spot on the driveway, right under the front lip of the bell housing. It is dark brown oil, not red trans fluid.

A few days ago I washed the whole area, including the oil pan and trans pan with mineral spirits. It was fairly clean and dry after that, now a few days later I tried to trace the leak.

The drips are coming from here:




These two bolts for the metal cover are pretty soaked, as are the seams between the plates:




I think they are wet from drips that come off the oil pan lip just next to this bolt (there is a drip forming on it in this pic):




Here's a wider shot of that area. Even with the missing bolt (replacement coming), there are no drips running down the oil pan cover itself:




There doesn't seem to be any oil on the outside of the upper cover plate running from the rear semi-circular seal where the oil pan meets the trans, but oil comes out between the cover plates:




So:

1. Do I have to replace the oil pan gasket?
2. If I do, should that stop the oil from getting into the bell housing and running out behind those thin metal covers?
3. Could there be another source of the leak from inside the bell housing?

 

I was getting the same symptoms when my lifter galley was leaking in my 4.9l. I would look on the side of the engine and see what might be leaking. if there isn't any signs about the oil pan gasket your best bet you'll be that. if it's above look at the oil sender unit or a anything along those lines.

 

I'm not sure where those other parts are that you said to check, the sender and its lines.

But regardless of what's going on above, it seems like the oil pan gasket is leaking. That corner with the missing bolt was glean, dry, and gray after I washed it, and now there's oil there again.

 

I would say it is the rear main seal.

 

Rear main seal is gonna be a bigger pain to replace than the oil pan gasket! Maybe I do the oil pan gasket and just live with whatever leaks remain.

 

replace missing bolt, check that they are all torqued to spec., then wait and see if you still have a leak.
while the rear main is a definite possibility, move cautiously here ... could have an oil leak at the rear of the intake manifold gasket.

 

If needed, where can I find instructions on how to remove and then replace the intake manifold? Do I need the big Ford shop manual if I want step by step with photos?

 

the ford shop manual doesnt have photos, just a couple of line drawings (which is really all you need). perhaps someone here, or on youtube, may have a photo tutorial ?
but lets not jump ahead ... determine the source of the leak first. main seal is often the culprit.

 

What's the best way to determine the leak? It's pretty hard to see anything back there. Should I take off the flywheel access panels or will that be a useless endeavor?

 

This was also my first thought. Things start at the top and flow down and back. What do the valve cover gaskets look like? How about back of the lower intake?

The 300 is a completely different animal. There is no lifter access on a V engine.

Why do you want to pull the intake and yes there are several threads on here on how to do it. It is not difficult to do except sometimes the Torx bolt in the middle is stubborn.

 

Everything is pretty dirty under the hood, but I will try and specifically clean around the valve cover gaskets, and then check again after I let the engine run a bit.

I do have the 5.8V, so it's hard to see what's going on in the back of it.

And I was asking about removing the intake manifold because it looked like there was some oil right at the gasket above the water pump, and around the distributor base. I'll have to give that a second washing to get it clean enough to investigate.

 

Is this the real-deal manual?





1996 Ford F 150 F 250 F 350 Bronco Super Duty Service Manual Set Gas 7 3L Diesel | eBay

I want instructions on how to take apart, remove, and replace any part of my 96 F250, and YouTube doesn't have it all.

 

Looks like what we had at the dealer back in the 90's. Wow, $140!!!! No thanks.

 

It's the cheapest one on ebay at the moment.

 

I wouldn't pay $140 either. These trucks are pretty simple. I've never needed the factory service manual to take one apart. The cheap Haynes/Chiltons manuals were always enough.