Oil leak

[FORD*DIEHARD]

To help explain the photo attached , this is looking down at the back of the engine from the top of a 302 . The space circled is the part I found oil in (I cleaned it prior to taking the photo) but since then more oil has accumulated there. Before I found this a shop said my valve covers are leaking. I dont think just a leaking valve cover would cause oil to accumulate at this spot. As much as I hope that I am wrong but it seems like the only logical explanation, would this point to the intake manifold gasket leaking?

I ran the engine and watched for leaks but nothing leaked while I was watching. When I drove it and stopped oil was on the ground as well as in the spot circled.

Thank you in advance for your time/help,

Sonny

 

[m_m70]

could be valve covers or the back of intake or both....I would get some oil dye, clean everything up real good, run it and see where the leaks are. The dye is under ten bucks and can save you some time and money.

 

[Broncobowsher]

Intake leak. Often called "china rail". Very common leak. I see an aftermarket intake. The factory is sealed there with cork, and good luck if any of those cork gaskets are still sealed. Replacement gaskets still come with the cork, don't use it. Nice fat bead of RTV is all you should need.

Not leaking at idle since there isn't the RPM to be flinging the oil up there. Drive it, more RPM, cam spins faster, oil flys. Under load, more cylinder pressure and more blowby to deal with. Didn't say excessive blowby, just normal blowby that the PCV should be taking care of.

Possible related, what do you have for crankcase ventilation? What is your PCV setup. Aftermarket intake, probably dealing with aftermarket carb, maybe valve covers? The PCV valve is only one part of the PCV system. What is your breather like?

 

[FORD*DIEHARD]

I installed a new Edlebrock manifold with a Rochester Qjet . The first time when installed the new manifold it leaked at the right front corner so I removed it and did it all over again. I purchased the best felpro gasket and used the rtv on both the front and rear China walls.

I tried revving the engine on my test trying to find the leak but as you mentioned (bronocbrowser) must not be enough pressure.

Here are some photos of my pcv and breather.

Is there a certain dye? Clean the area Just pour it in the oil, drive it around and it will make it easier to locate the area(s) it's coming from? Do you need to change the oil after you do this or does the dye not affect the oil?

 

[DirtDonk]

Is the vacuum source for the PCV valve to the carb, or to the back of the manifold (vacuum tree?)?

 

[B RON CO]

Hi, Tracer Products make dye for leak detection. You do not have to change the oil. I would start with going over the valve cover bolts, just make sure they are all snug, don't over do it. Or else I would change the valve cover gaskets. That is much easier than doing the intake manifold. Good luck

 

[ared77]

Here's another one and the light to make it show up better in the box.

 

[Broncobowsher]

Looks like you have a decent crankcase venting system. I'll scratch that off the list. If the PCV valve wasn't working I would expect a lot more oil dribble out the breather/filler.

So I'll go with a normal leak. That UV dye can show some pretty interesting trails. The hardest part will be getting that light and an eyeball back there to see what is really going on. Oil follows the same rule of gravity, it goes down. The two ways it goes up is if something pushes it up or there is some fiber that wicks it up. And I don't see anything that would be wicking it up. Any air on the outside of the engine pushing it up would also be spraying it around making a huge mess that would be really smelly. So I am going with gravity and leaking from above that point. UV dye will tell you if that is the valve cover or the intake gasket.