Where is this oil coming from?

That's weird..
Here's the junction on QV I've got on the bench. I'll dig thru the files for pics with it all apart.
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I don't have a picture but if memory serves the oil passage from the pump to the oil cooler output terminates in the back of the block and is sealed off by a steel, allen plug, the same as an oil drain plug.Its really the only source for oil in that area. That allowed a through drilling of the oil passage from end to end of the block casting.

It might also be one of the tapered alloy core type plugs. I know for sure the main oil gallery above the crankshaft is sealed with a shouldered steel plug. Interestingly out of all my photos I do not have a single picture of the back of the block and the parts books do not really show much either.

 

Yes. It is an alloy core plug kind of thing. Not so much on the V8s but I have had many of those leak on various models.
Usually not too hard to change.

 

Also just above that is the cavity for the oil return off the back of the head, I've seen it where the gasket between the block and mid plate leaks into the chamber where the oil pressure gallery plug is as well. So it's also likely to be the gasket failure. Those plugs can be a real bugger to remove since they're a soft aluminum.

 

Metric taper plug for the oil galley down in that corner. Those are a real bugger to remove. Any of the alloy ones really.

 

Drill most of it out, and if it doesn't just spin out with an easy out tap around the circumference.with a chisel to collapse it some usually come right out.
If its gone 30 years with no coolant changes thats different.

 

Then its really easy. There is only one possibility.

 

My vote is gasket, seen it a couple times.

 

I like simple fixes.. that's good news!

 

Can that plate be removed to replace the gasket with the motor in the vehicle?

Thanks

 

Yes. Once the bell housing comes out and the flywheel is removed, its the next section. That plate also holds the main crankshaft seal.
It's a tight space working in the engine bay but doable.

 

Interesting thread... I've got a small leak there and was trying to figure out source of leak. I'll check these new spots.

 

You are speaking to a 328 correct? I was wondering, on a 308? I haven't seen the underside of a 328, but I assume its different enough this may affect things? I didn't know on a 308 if there was room to get it out over that lower gear rod (for a lack of proper term).

jim

 

Yeah, I have a leak there, kinda in the same spot as yours was pooling and then leaking. Problem is engine is in the car, lol. I've been told it can't be done in the 308. I know this is blasphemy, but could one open it up, slid down the rod a bit, clean up the gasket then use some liquid gasket maker?

 

I've done it, but I seem to recall pulling the big studs. Worst case, engine pull.