I had a bad oil pressure sensor that spewed oil through the connector, and ran down the passenger side of the transmission. I replaced it, and all was fine for a couple years. Started leaking again the same way, and yep...the sensor was leaking again. Replaced it and it's good. The first sign of that problem has been a flickering/erratic oil pressure reading, plus the leaking.
So...I had to replace the distributor due to bad bushings, and it only has a paper gasket on the top...and I'm guessing in normal operation, oil doesn't put any pressure on that...but, there is a puddle of oil near the distributor, (I'm running dye in the motor) that's not "deep" enough to overflow and run down the side of the bellhousing...but it might when running down the road? The lands on the distributor were kinda rough where the casting (plastic) seams are, so I cleaned them up and put some gasket compound under the gasket. But...assuming this is where it's leaking, how does the oil get way up there?
Another thing, is that I keep reading how loose intake manifold bolts can cause a leak...but why is there oil in the intake manifold?
I've tightened the bolts there, and at the valve covers...but I keep getting a substantial drip that comes from above (where it's almost impossible to see) runs over the starter and drips off the starter bolts.

I've tried to find a good pic of what might leak back there...just an engine on a hoist or some other picture...but no luck so far.
I added a can of AT-205, and don't see much change. I don't have a boroscope...yet. But Christmas is coming...

I need to figure this out. I use this to pull my fishing boat, so you can imagine how critical it is to get this back on the road.
Any suggestions?

 

Have you replaced the lower intake manifold gaskets? Do you have any coolant in the oil?

George

 

No coolant in the oil, and no oil in the coolant.
I haven't replaced the lower intake manifold gaskets...but I'm wondering why that can cause an oil leak...how/why is oil in the intake manifold? Nothing to oil in there.

 

 

Ok...with the help of my brother, who is a Chevy guy...I understand how oil can leak out of the intake gasket. The last car I had the intake manifold off, was an overhead cam Maxima, so no push rods/lifters, rocker arms, etc.
This oil isn't under pressure...so for the amount of oil it's leaking it must be a pretty good leak!

Thanks for the patience.

 

George...what is the shaft with the offset shapes running right down the middle?

 

https://blazerforum.com/forum/2nd-ge...k-hell-102905/

The documents in post #17 are what you need if you decide to tackle this job and they have pictures of our exact engine.

George

 

Balance shaft

George

 

Thank you, George!
Now I get it.

 

The LIM gaskets are a weak point in this engine and most of us wind up doing this job at some point. If you decide to do this job be sure to use top quality gaskets like Felpro and be very careful with the RTV beads and the torque sequence.


George