Hunting for oil leaks on my 302

So, Elain the F150 is a little leaky.... I'm getting dripping in several places, the most obvious is off of the transmission inspection cover (I think).  The engine compartment is pretty oily as well so that hasn't helped me find things.  In any case, I want to make sure oil isn't running off elsewhere before assuming a bad rear main.  The drivers side valve cover has all kinds of oil on and around it, so I assumed it could use changing, I've snugged the bolts several times already.  So today I changed it.  

In hindsight, I think the old cork gasket was fine but not torqued enough, and not the problem.  Here are some pictures from the job.  

Here's the valve area and valve cover as I found them.  



I got the gasket scraped off and cleaned the valve cover


If you look to the left of the head, where it meets the intake manifold there's a bunch of oil pooled, sort of in the middle, front to back.  I was unsure if this was coming from the valve cover or elsewhere... so I made sure to clean it up before test driving the truck.  


After a 10 minute test drive... it's back.


So, is it possible that I have excessive crank case pressure and its pushing oil up through those bolts? The head also has a little cutout right there (see below), can oil get pushed through that?


Gave her the full craigslist rebuild when I was working.


Right before I started the test drive I saw oil leaking from the oil sending unit, so that's something I can get next.  

Oil dripping off of the tranny's inspection cover is usually from the rear main.

On the oil pooling between the head and the intake manifold, I'm going to guess that it is because the valve cover isn't sealing there.  Typically what happens is that the valve covers leak so people tighten the bolts down more, which bends the valve cover right below the bolt head.  And then when you put new gaskets in if you don't flatten the valve cover the gasket hits there but then doesn't hit either side of that point and you have a leak.

I lay the valve cover upside down on the edge of my work table and use a small ballpein hammer to drive the dent at the bolt holes out, being careful to not go too far the other way.

red1980F150 wrote

So, is it possible that I have excessive crank case pressure and its pushing oil up through those bolts? The head also has a little cutout right there (see below), can oil get pushed through that?

That's a blind hole. It doesn't go anywhere.

Yeah, I have this gnawing feeling that the rear main needs to be changed.  I just wanted to make sure it wasn't something simple before removing the engine.  The front main went, and in a big way, last winter.  I think it's springing leaks because the rings don't seal as good as they should anymore, but I haven't done anything to prove that theory, just observed blow-by.  

The truck runs so good it's incredible, its extremely pleasant.  It starts on the first crank with a single pump, is quiet, and shifts smooth.  It just leaks too much, I've got about a 1x2 foot patch (at least) of oil from it on my driveway.  How good it runs is another thing making me cringe at the thought of taking it down for an extended period, but if I have too... then that's just the way it is.  I guess unless I want to pony up money to pay someone to do it for me.  But I figure if I pull the engine then I might as well do some other things too, like put a ZF 5 speed in it and make a few changes to slightly improve the top end (if I do this I'll probably ask for recommendations).

Back on topic, I guess, I didn't think the valve cover flange seemed very distorted, but it wasn't quite perfectly flat.  I put one of the nice fel pro rubber/metallic gaskets in too.  So I guess if it is the valve cover causing oil to pool then at least I can take it off without ruining the gasket.  On this topic, my chilton manual said the torque spec on the valve cover was 132-168 in-lbs, this seemed like a lot to me because I think it's enough to distort the valve cover.  Does that seem right?

Rembrant: Thanks, I figured as much because the same cutout is on the other side and there's no leak, but I haven't built one of these so I didn't know exactly what's going on inside there.  

The leak is a shame on an engine that runs so well.  But it isn't terribly hard to pull the engine and reseal it.

As for the torque on the valve covers, you've run into exactly why I do NOT use Chiltons or Clymer books.  They have too many errors.  Ford's factory shop manuals do as well, but far fewer as they can't afford to have their mechanics ruining things on their dime.

The FSM section (Documentation/Engine/Windsor) says that the spec is 3-5 ft-lbs.  Your book says 11-14.  Big difference.

Use a stubby 1/4" drive ratch to tighten them as it will not give you much to grab to over TQ the bolts.

Dont over look the rear of the intake seal between the intake & block.
If this gasket is bad the oil can leak down the back of the motor and drip out the bottom looking like a bad rear main seal.
Use a mirror and light to get a good look back there.
Dave ----

FuzzFace2 wrote

Dont over look the rear of the intake seal between the intake & block.
If this gasket is bad the oil can leak down the back of the motor and drip out the bottom looking like a bad rear main seal.
Use a mirror and light to get a good look back there.
Dave ----

Amen!  I've had two engines, that others put together, which had horrible leaks there.  And it'll look like a rear main leak.