Need help with upper engine oil leak...

[munsonbw]

I know this sounds simple enough, but I am looking for some likely candidates before I rip into the engine too deep.

What I have is oil pooling on top of the timing cover and block (i.e. both sides of the gasket). The pool is on both right and left sides of the cover as well. I have cleaned up the engine as much as I could, but am still having issues pinpointing the leak. There seems to be too much oil to find the "trail" back to the source. The timing chain was replaced a while back, really before I started driving it, so I can't remember whether it used to leak or not. Anyhow the gaskets are new and the cover is tight.

I get about two ounces of oil pooling every 75 miles, so I am thinking that the oil source is most likely under pressure. That seems to rule out the cover, right? What about the intake or distributor?

Any help is appreciated. If I don't get any leads I'll just start replacing gaskets. Its a 36 year old motor anyway!

Cheers,
Ben

 

[Skiddy]

Sounds like your intake gasket is leaking

 

[airman]

we sometimes add dye to oil in our air compressors' syn fluid to find tough leaks. If you know a guy that does HVAC work he may have some. You use a black light to find the source.

What is your oil pressure by the way? Any noticable performance degradation?

Jeff in AZ

 

[Mikey]

Start easy then work to more difficult:

1). Distributor O-ring
2). Valve Cover Gasket
3). Intake Oil Seal(s)

I can't think of anything else unless oil is leaking low and whipping up (unlikely).

Valve cover gaskets are notorious for leaking but usually at the back, dribbling down the block and making one feel that the rear main seal is shot. A good aluminum valve cover is usually the ticket. On the 5.0, use the SVO steel-core gasket with rubber ring molded to it. Expensive but it works!

Good luck,
Mikey

 

[Lttrbox]

I vote for the intake also. Just behind the dizzy. Mine also gave way there and did what you describe.

 

[74bronc]

I vote for the distributor o-ring seal. They don't replaced that often and I would bet yours is dried out and crusty. I would start there because it is easy to change and only costs a buck or two. Then I would do valve covers, since they are cheap and easy to do as well. Then, I would look at the front intake manifold seal. I would leave that till last because it is harder to do and I am lazy ;D

 

[Broncobowsher]

I vote for intake gasket.
Fluids usually run downhill.
Smallblocks are known for the vally seals leaking, both front and rear.
Throw in some valve cover gaskets while you are in there.

 

[Mikey]

I agree! I'm lazy too! Also, I just noticed, the list is in order of probability, too. How convenient! ;D
Mikey

 

[wildbill]

;D ;D ;D I would bet on the intake leak at the front and back real common on the older motors good luck. Bill %)

 

[airman]

Somehow after reading this I want new valve covers?

 

[Smedley]

Mine is doing the same thing. To make is worse is as the oil pools above the time chain cover the fan is blowing it all over the place making it difficult to pin point the culprit. Lots of good advice though, at least now I know where to get started.

Thanks
Will

 

[munsonbw]

Lots of great info! I think I will follow the general consesus and replace he dizzy O-ring first. Valve cover gasket are new (1000 miles). So that pretty much leaves the dist. and intake.

Hmm, while I'm replacing the gasket maybe I should replace the manifold and the carb and new heads.... wait, no just the gasket.

Thanks guys.

 

[taxx]

Just to bring this back to life and not start a new dupe thread. I am in the process of upgrading to an electric ignition and checking the mixture and timing and I have been inspecting more to find the source of my oil and coolant leaks. not to mention the smell of gass I get which could either be a leak or a poor burn. Here is what I found:

The pics show two pools of oil different than the other in the front of the engine. #1 on the second pic is the same as the first pic just zoomed out. Its a puddle and the only two places I could see if coming from are the valve covers and the intake manifold. Well the valve covers are dry all the way around and the intake is wet all teh way around. It looks like it has to be that if it is possible for oil to leak out of there (been a while since I had any sort of intake off and cant remember if oil is in it or not, but I can't see why not). The leak number 2 looks like it is coming from that bolt(or nut) which would lead me to believe the gasket at the bottom is leaking and allowing it to come up through there. The third pic shows around the base of the distro and I know coolant can't leak out of there, so it seems to be running down hill and pooling. What do you think?

http://www.haughs.net/gallery/albums/bronco-engine/DSC01252.jpg

 

[taxx]

Hmm, while I'm replacing the gasket maybe I should replace the manifold and the carb and new heads.... wait, no just the gasket.

side note: glad I am not the only one like that! :-*

 

[munsonbw]

taxxman2k,

The first two pics look a lot like what I was seeing, and a new manifold gasket should fix you right up. The third pic with the coolant I would say is your timing cover gasket. Coolant flows through this cover to the pump, and there is no coolant present to the dist.

The intake job is pretty easy, the timing cover is a little more involved. Have you replaced your chain lately? How about front main seal leaks? You can fix these and more when you tackle the cover!

Good luck,
Ben