Inliners International Forums General Discussion Engines Oil Leak 250 Intergrated head

On this 81 model truck, 250 I6 with intergrated head...
There is an oil leak on the very very back that leaves a goo on the block. The leak IS NOT coming from the Valve cover, it seems to be coming from IN BETWEEN the Intake & Exhaust manifolds.

Are there any diagrams or pictures I can look at before I tear into this thing. I fear the bolts breaking when taking off the exhaust manifold... so if I could find a parts drawing, that would be great.

P B D

You don't seem to be getting much help with your integrate head issue. I have done a head swap OEM to OEM on my '79 C10 with the integrated head. There is no oil exchange that I saw between the intke and exhaust manifolds. As far as a diagram, I have found none. However, if you intend to pull the head, buy the gasket set and look at it. You can get a good idea how it all goes together from the gaskets. Your concerns regarding the bolts that secure the exhaust manifold to the intake are not unfounded. I would suggest that you pull the entire assembly as one unit, head and exhaust. Then you can work the exhaust manifold removal on the bench where you can better manipulate getting penetrating oil into the threads and carefully removing the bolts. Take your time. If you have a head exchange dealer ask him if you can look at an integrated head like yours.

Regards,
Ken

Thanks for the reply. I bought a Chiltons book Today. It did not have pictures I wanted but had a narrative that explained some stuff about the integrated head.

I hate to have to tear into it, but then maybe I can paint the engine Orange instead of that dull GM blue.

When I pulled mine I painted the new head and the valve cover Chevy orange. Looks better than the blue GM began using. Keep in mind that any 250 head from earlier than the integrated head years will bolt onto your engine. Doing that will enable you to use an Offy or Clifford intake and perhaps one of T Langdon's carbs and his cast iron headers. If you do not have to hassle a smog inspect every year or two, then you can leave the setup on and be done with the integrated head (hereafter to be know as the IH. The IH leaves you very few if any options.

Hope this helps.
Ken

Next stupid Question... will a regular valve cover fit on the IH
The IH valve cover looks like that kid from school wearing a headband to hold his braces on.

P.B.D.
I have not seen yours. A valve cover from an earlier head will not fit on my '79 250. Mine has multiple inlets on it for emission (read: smog crap) controls. Does Arkansas require smog equipment requirements or can you modify your engine "legally"?
EV

Does the engine in question smoke or use oil? The black goo, could be burnt oil from the valve guides leaking out of the exhaust flange. The oil is pumped up the push rods and drains back to the block through holes by the push rods, there is no oil on the intake side of the head. Check the PVC fittings and breather tubes. The valve cover is most likely the source, its pretty hard to get them sealed. Joe

Being from Louisiana myself, I think all Arkansas requires is a license plate to legally drive. That and insurance maybe.

We dont have vehicle inspections in Arkansas so Emissions can be modified without fear of EPA or Revenuers.

I will check the valve cover gasket. I just got the vehicle recently and have changed the oil twice to clean the internals up.
It was a Farm Truck since 1981 and needs some TLC.

P.B.D.,
Joe H. is likely correct. Install a new valve cover gasket. Use blue RTV to secure the gasket to the cleaned gasket surface on the valve cover. Then bolt it back onto the head with no compound between the gasket and the clean head surface.
Ken

I got to crawl under the truck today. The oil leak is not actually the valve cover... The vehicle has the Integrated Head and the leak is where the integrated exhaust manifold bolts to the lower exhaust manifold. It looks as if... there was some backpressure on the exhaust system and it blew a gasket.

So I would have to take the whole head off to fix the goo leak.
I will do it, but not this weekend. Thanks for all your input gentlemen.