After removing several items including the distributor I was able to get a complete view of the rear of the intake to block seam....NO oil leaking there.

So it is either the leak is at the rear of the oil pan or it is the rear main seal.

I have checked the two rear bolts on the oil pan...they are tight.

The oil begins to drip out of the hole in the bell housing after about 5 minutes of engine running and then stops dripping shortly after the engine is off. I think it is the rear main seal.....so guess it is time to try some of that Lucas oil treatment.

Perhaps I will replace the seal in the future...but not going to happen at this time.

 

Any luck with the oil treatment? I've been chasing a leak, also. Replaced the oil cooler lines and gasket. Gasket twice, since the "help" brand was too thick and the adapter was still leaking. Just finished that, (with a gasket/o ring set from a Chevy dealer) and I still have a leak. It sounds identical to yours. It's coming from the small hole in the bell housing dust cover (inspection cover?). Mine appears to only leak when the engine is turned off. It's leaking at a rate of about one quart per 400 miles.

I really don't want to replace the rear main.

 

I have a 2002 and it has a little oil leak after I turn then engine off also. Did you figure out what your issue was? Mine seems to be leaking from the small hole in the bell housing cover also.

 

Guys, quit spinnin your wheels so much.... Oil additives don't fix the problem, they are just bandages and will only last a few weeks...! Pull the trans and replace the rear main seal. I have a 1988 with the 2.8 engine. I chased the same oil leaks till I got to where your at. Like a dog chasing it's tail. While your at it, change the front seal in the transmission too. If ya'llll need help I have all the diagrams and can answer all your questions at rynoauto.org

 

Thanks..... I am thinking about doing that.... was just curious what was found out about this

 

For some unknown reason, I no longer have an oil leak. I did not put an additive or anything into the oil....it just stopped dripping.....and I have no idea whatsoever why.

 

Mine did the same thing!! Replaced the oil adapter gasket with the dealer part like I said, but I still noticed oil leaking from the small hole in the inspection cover, after I turned the engine off. Resigned myself to a leaky blazer.

The next time I drove it, no leak! I even parked on a nice clean spot at school, and three hours later when class was out, it was still clean. Haven't lost any oil on the dipstick, either.

The only think I can think of is the oil wasn't actually coming from the hole, but from higher up on the engine and running down. The hole is at the lowest point, so that's where the oil ended up dropping off.

 

I know for sure that the oil was coming from the small hole in the bell housing...I was under the vehicle watching. No oil running down anywhere on the outside, the oil dripped out of the small hole.

The only thing that changed was the oil has a few hunderd miles on it now. I keep checking for oil spot on the driveway, but so far so good.

 

Luck has nothing to do with it and I've seen it a-lot. Check the front of the block. WIND at high speeds does real crazy things to oil traces.
Here's what ya do to find an oil leak. The PCV valve is the key participant here. If it's good, then the factor of Positive Crankcase Ventilation is working. The engine pulls air in on every stroke. The crankcase is a sealed unit, correct. well if your adding oil pressure into the top of the block, the air coming with it needs to be ventilated out through the PCV valve and into the intake in order to keep in any BYPASS GASES from escaping into the environment and cycle them into the combustion chamber again and burn it off.
Grab a pair of long handled needle nose pliers, locate the PCV return hose going into the valve cover and start the vehicle. light the area up really good first. While it's idling pinch off the hose and hold it for a second and look for a squirting leak front & back. Be quick about looking and pay close attention to how long you pinch the hose off. My 1976 Toyota pickup with an R22 squirted outta the front case cover and I finally found the leak. The pressure will build up so don't do it for longer then a few seconds or you could blow the seals or create a leak. The point is, have someone helping you with a flashlight under the vehicle and looking at the same time front to back rapidly.. BE SAFE.... checkout my website I have videos of all the work I do. and ya better pay attention to your oil level on LEVEL GROUND TOO!!! Years ago I ran my Toyota down to a quart and a half once. Light came on during a hard turn and I noticed it was time to check it... LOL

 

A blocked pcv will definitely cause a leak. When I was younger and dumber, I swapped manifolds on my '73 chevelle. I decided I didn't need no stinkin pcv. A few days later, I notice oil burning smell. It had pushed out my valve cover gaskets and caused a leak. Needless to say, after new gaskets, and a functional pcv, I was leak free again!