Hello..long time since I've been here..I'm looking to do a freshen up and have 2 weird leaks to deter..one on top of the fuel pump around the exit flange,I have smelled the oil, I can't sense fuel in the oil,,but.??...can oil follow up the arm through the diaphrams...?, and the other, underneath cylinder 2 and 3 exhaust manifold port, the top side is dry no leaks...the plugs are burning well..I might see a faint oil burn in that exhuast pipe but it dissipates quickly like steam...I'm going to try to figure out how to get some pics on..

Man..I cannot find "file manager". Is it not viewable from Android ops

To post pics on forums you have to use a photo hosting website like imageshack or photobucket and others.

[img]http://[IMG]http://i50.photobucket.com/albums/f...40076.jpg[/img][/img]

Thanks CNC..its been awhile

I had a fuel pump go bad and leak like that at first. Then, later, I had oil squirting out of the weep hole on the side of the fuel pump. Hard to find for me, though, because I had a mechanical fan at the time and the oil didn't leak until I was in the higher RPM's. The fan sprayed the oil all around the engine bay.

Replaced the fuel pump and no problems since. Cheap fix.


The other leak is probably the valve cover. Oil travels pretty far when it leaks.

I would say valve cover, as it is finicky if you don't have the bolts snug. But I don't see any oil on the cylinder head above the manifolds, or on the intake? It looks like it might be coming from the had gasket under the forward intakes. Perhaps the lump allen bolt needs torquing?

Love the old truck air cleaner. Would like to see some overall shots of the engine bay. Looks pretty.

Thanks guys..I am going to replace the pump..no problem..the top side is dry...if the lump bolt in the intake is out of spec can it leak oil over to the exhuast side over or under the head gasket?? It didn't even think oil ran that area..the return holes are on the opposite side of the head...maybe the darn head is cracked...

Here is a compartment shot..before the crinkle paint came off that cover.. That kinda started me wanting to freshen it up.. [img]http://[IMG]http://i50.photobucket.com/albums/f320/fingersix/IMG_9778.jpg[/img][/img]

Nice engine bay. Very clean. Looks like you're running coolant the heater plate. Yeah the black crinkle valve cover looks better than the chrome one.

Yeah, you're probably right on the oil return, nothing on that side of the head but coolant. It must be oil getting out from under the valve cover or through a crack. I just don't see where it is coming from above the manifolds.

That head leak seems to be coming from the exhaust port.
Wonder if the exhaust guide and seal are passing oil when it is shut off. It then leaks from the port.

Makes sense. That means the seal or guide are leaking, as well as the manifold gasket.

Couldn't possibly be that much oil from the exhaust guide and seal. During normal run times it would be pushed out the exhaust too fast to leak that much and when the engine is shut off the oil would have to defy gravity to go up the boss and down the valve stem.

I have the same leak. I think it's a combination of things. I think it's the cheap chrome valve cover (we have the same one... doesn't seal too well, does it?) and the air filter on the valve cover. I think I have bad valve guides and seals so a head job is in my near future (tax refund? Could do it now but the wife.... well... she says I spend too much on the car as it is!) but for now I'm trying to mitigate the leak as much as possible.

I was inspired by your wrinkle paint and decided to dig out my original valve cover and do the same last night. It's still drying so I won't install it until tomorrow. I'm hoping it seals up a whole lot better and looks good while at it.

If I like the look I'll probably paint my air filter lid with the same stuff and just have chrome accents on the engine.

The OEM cover seals much better than the flimsy chrome cover. I've been fighting it for a year now and I'm done. If this works but doesn't look good I'll buy a cast and polished cover.



I also plan on fixing that rats nest of plug wires this weekend as well as going through my carb again.

Man..I know that top side is dry..from looking when I took the black one off.the oil was present before the chrome one...the crinkle failed after 10 years..that's what confused me looking at this..I will look real close when I swap the black one on..see if I can see any crack or anything..I will pull the manifolds too...see if that tells anything..

Hi,
I had a couple thoughts regarding the oil leak problem with the valve cover or manifold.

First I see that the chrome valve cover on gbauer's engine is the cheap import, but the cover in fingersix's photo shows a factory valve cover(see script?). I consider the import scrap. But the factory cover ought to seal assuming it's straight and a good gasket installed.
As to the exhaust leaking oil, I'm thinking you might want to pull the valve cover and make sure the oil return holes in the head are open. If oil builds up because it can't return to the pan fast enough it could leak down guide when engine is shut off. Take a look for cracks on valve guide bosses too.

The aftermarket manifolds some times don't play well together where they meet on the mounting surface. If one or both flanges are a hair too wide and they don't have clearance next to each other they may not fit flush to the head and as you tighten the bolts down one runner may bow out away from head.
In my case it made for a hard to find vacuum leak as the gap was at bottom of center intake port. I didn't find it till gas started leaking out and down block. ( yes it was hard to start with a big vacuum leak!)
Hope this helps. Let us all know what you find.

OK..I got the manifolds off....my assumption is oil seeping from the head block surface right at the gasket below a freeze plug and it might run along till the mid exhuast thins it out enough to run down the block...???? I am going to try to get pics on again..here goes..

its really wet at the gasket location right around 1-2 intake, from like under the freeze plug to the set screw for the lump,, and run down the line to the middle exhaust,,,, could I have not torqued the head exactly, properly and over the years got some warping and the oil travels under the head gasket from the return holes,,,??? looks like i may be pulling the head,,,what do you guys think,,?

I'll still bet real money it's the valve cover and not the head. I've found oil has a magical way of traveling...

Did you check the head bolt torque. I would check it just to see if it is still tight and even.

Nope. Nope . nope on the valve cover..its dry as a bone around..I was trying to show that with the one pic from the top...I'm going to look again...for the torque..its been so many years is there a different spec for the Allen, having to use an extension piece and the adapter..doesn't it loose pounds for the multiple pieces from my wrench to the head.?

You can tell from the last few pics that the front intake port is real oily and the lower half of the intake gasket is oil soaked. It also looks like the rear intake port is as well.

CNC..the gasket isn't there..that is impression...but I agree oily...??? Is that a tell tail for anything...

Yes, its a sign of something! Also if the gasket is gone oil was leaking behind it then for the gasket surface on the head to be oil soaked. How fresh is the head work?

The engine and head is about 12 or 13 years it is a sissel done head and Larry "twisted 6" did the lumps...seems like forever ago..

I swapped manifolds somewhere in the middle from a Clifford to the offy...

I have another theory for you to check. Another inliner pointed this out to me. See if you PCV is passing oil into the intake manifold. It can than track into a certain port and pollute that cylinder and show up tracking out the intake port.

Well I know I am going to take a hammering on this......lol..I sucked on the hose...with even the lightest pressure I can breath..with just alittle force it feels wide open.....how do you really check these...

You would think the back port would be dirty...the hose plumbs in right in that runner..

If the inside of the intake manifold runners are also oily, it could indicate the pcv valve is allowing oil to be drawn thru it into the engine. Is the valve cover baffled where the pcv installs into it.

Yes both covers had been baffled...the mercruiser one I added...I don't remember why stuff was cut out.

Here is some runner shots...I thought they were clean...????

Ive taken this apart as clean as i could no rubbing or wiping,,its hard to separate oil residue and gasoline goo,,,,

You'll need to run your fingers down in the plenum under the carb and onto the floor of the intake into the intake runners to verify this.

From what I'm reading..pcv valves should be practically closed at idle...high vacume conditions...from my " suck" test..it seemed wide open....??? I see no oil in the valve or line...could it be clean enough to be clear and thin till it finds its way outside..?

The baffling in both valve covers is really not very adequate to prevent oil being sucked into the engine thru the pcv valve. The only other thing that can be possibly be causing this is the valve seals have failed and/or intake guides excessively worn.

??? What kind of baffling is suggested..the one cover is a GM..

I would suggest a better PCV. The stuff that ends up in parts stores is not so good in quality these days. Maybe buy a PCv for a different application, such as a smaller engine like a 153.
Who knows, some calculator guy in the factory may have decided to lump the 292 PCV with Larger V8 PCV units. Allowing it to move too much air.

The baffling in the GM VC is sufficient.

Fwiw the seals in my head leaked horribly. I ran my fingers in the intake ports and got really oily fingers. It was pooling. Look for my "two stroke" posting.

I had some exhaust leaks, but no oil leaks anywhere. I could imagine oil leaking down the manifold but it seems it would have to have vacuum leak too.

Just ran my fingers into the ports.the top and back side of the lump feel like raw alum..not slick and the valve below the head surface also feels dry..the top of the valves seem alittle sooty..I would of thought with fuel they would be clean as a whistle...
Tom..I was going to put the merc. VC back on..should I not..the front hole is oil fill..which I use a breather cap and the second one I added that baffle to the hole..does it need filled or extended...maybe I'll get something else..

I don't remember what I have for valve seals...I can tell the are white in color with a silver metal band...

I think I have a similar issue and, like you, I believe it's oil coming through the PCV. I think I have bad valve guides causing the problem to be worse than normal.

Sometimes I'll get a bit of smoke coming out the valve cover vent. I know I need to get my head rebuilt. I believe the valve cover area is being pressurized because of a leaking valve guide/seal. Using stock seals and I don't think the heads were ever set up to take new, lead-free gas.

It's on my to-do list.

I notice it especially when I run the car hard.

Fingersix,
Not sure what you mean with the Merc VC. Maybe try some pics.

Another thing it could be. Fuel will pool in the intake after engine is off. The lump in the head would impede fuel gravity running into the valves. Maybe it pools at the intake port and boils out from the warm engine leaving behind the dark crud that can leak out past the gasket. Fuel residual sludge.

Tom..I am referring to the mercruiser cover..it is the one above the double baffled GM cover in the pic...I was wanting to reuse that one over the chrome....
Oh man..have you opened a can of worms..I also thought that...I have never been able to keep fuel in the Qjet bowl..In a few days it will be dry and crank crank crank to fill it up before it will fire..I assumed it was evaporating..I keep smelling the oil to see if it's washed past the piston but it can't climb the lump.....I've had the carb gone thru twice by a reputable guy...it has the bottom plugs epoxied...I even tried to accumulate some sludge and light it in fire to see if it was fuel..would it turn that brown leaking thru the gasket and picking up dirt and stuff..? Mmmmm

The Merc covers I have, have decent baffles built into them, same as your pic shows.
I have no worries about that cover.

If it's not oil, then it is fuel. You have certainly seen how carbs can get that dirty look to them. It is from the fuel. Bet it is the same thing for you.