I have replaced the pcv valve and its grommets, tightened valve cover bolts. I do not believe that the valve covers have anything to do with the leak as it is not wet and I also sprayed out the engine bay a few weeks back. The oil leak was usually just a few drops per day however in the past few days the leak has increased significantly. It is now a 6x6 inch puddle after just sitting for 7 hours. Oddly enough my oil level, according to the dipstick, has not dropped significantly (like you’d think it would for the increased leakage). The area is a mess underneath the car. Oil is everywhere around the pan and it is wet. It is dripping off of places around the pan and a few of the lines have oil on them. I think this may be the oil pan gasket; but I’d like to get some opinions before I replace it or pay a mechanic to. Here are some pictures. (Also the thing with the two circles in first picture seems to be wettest)

This seems to be wettest part.

 

The remote oil cooler hoses are a common failure point on these engines. I also had the o-ring in the adapter between the oil cooler hoses and the block break and cause a leak there.

 

I’ll have to check that out because if I am remembering correctly I am pretty sure that I saw some dried up and crusted oil on ends of those lines.

 

the cleaner parts are indicative of the leak. The oil washes away the dirt.

I agree with Christine on starting to look into the oil line adapter below the block.

If not damaged the Blazer oil pans are not known to leak.

 

Does anyone know what this part circled in red is? After cleaning all of the other parts the drip is now only coming mostly from this part. Looks like a line is running into it above the drip.

 

It looks like part 437 or 407 here:
https:/nemigaparts.com/cat_spares/epc/chevrolet/54s-t/00/tx00-046/

These would be the adapters for the remote oil cooler lines or remote oil filter lines (which also can have oil coing), respectively.

The o-ring on the adapter on my 92 4wd broke causing a good sized leak. When I replaced my remote cooling lines, I also replaced the o-ring and gasket at the adapter.

 

Thanks Christine,
I’ll have to get it up on my ramps again to check how much oil is there again, but, I will probably be replacing these… When its warmer, of course.

 

If you replace the gasket and o-ring for the adapter, something that worked for me to hold the gasket in place was to use a thin layer of Vaseline between the gasket and the underside of the engine to hold it in place. It's kind of cramped under there and the Vaseline acts a bit like a third hand.

 

What brand would you suggest for the gasket, O-ring, and the lines themselves? Ive seen a few people who used the dorman lines have had the leak back 20,000 miles later. What brand would you suggest?

Also, I am reading that the engine has to be lifted to replace the O Ring and gasket for the adapter… is this true?

 

I used FelPro gaskets and o-rings but I'd also be good with GM ones.

For the hoses, I used GM ones. Assuming mine were original, I got over 120k miles out of them. There might be better ones, but I don't know what brands those would be. There might be some posts on the forum on that topic.

On my 99, 4wd, 4dr, I didn't have to raise the engine to replace the gasket, o-ring, or oil lines although it is a tight squeeze there. A big help was to put a dab of petroleum jelly between the engine block and the gasket to hold the gasket in place.

I learned that trick from posts by engine rebuilders who put petroleum jelly in newly installed oil pumps. If I remember correctly, they do this to prime them, with the jelly disolving into the oil.