Oil Leak

I am having a problem with My 86 blazer, i just got in running Good and, not even a day later i noticed i had a significant oil leak. I thought that the leak was coming grom the valve cover and tightened that down( it was pretty loose) I wiped the oil off the bottom to see if more was still leaking. I did check the valve cover and there is no oil leak from arround the edge. This morning when i got up there was oil leaking all down the bottom. I am not sure what could be leaking and was hoping that someone might have an idea or maybe and engine diagram they could send me.

You almost have to clean the engine so that you can see where it is coming from. It could still be the valve covers. You really haven't said where the drip is occurring. If in the front of the engine, could be timing cover, front seal or if the rear, oil filter housing, rear main, oil pressure sending unit, oil pan, is this enough to look at. Also, you haven't stated the engine.

It is the 2.8l V6 4x4. The leak is on the back side of the engine and is leaking down around the trany and onto the exhaust which is why i originaly noticed it because it smelt like i was burning oil. I was talking with my father in law and we were starting to wonder if it could be the rear engine seal. After looking at it it seemed that most of the oil was around that area where the engine and trany join. The leaking down arroun on either side. I did check the oil pan and it did not seem to have that much oil on it. The oil that was on it was all on the side closest to the trany.

Ok, if the rear main seal is leaking, depending upon how heavy the leak is, it will normally drip from the weep hole in the bottom of the bell housing.

You mentioned leaking down around. I'm going to guess that even though you said you tightened the valve covers, I would be willing to bet you need new ones.

I do have new ones because that is originaly what i thought the problem was too, we thought we would see how loose it was and when it was really loose we thought we would just tighten it down to see if that fixed it. I think i will start with replacing those and when we get some of the stuff off around the top of the engine i will see if i can get a better look at the back and see if i can find any other possible leaks.

About 4 years ago, I did the valve seals in my personal Blazer, '93, 4.3 L. There are times that I hate to work on my own car for I do that type of work everyday. Now that you see what my mindset was, here comes the story.

I was in a hurry to finish and thought I had the valve covers on properly with the gaskets, but I didn't. On the passenger side, the gasket curved in and this created an oil leak. And as you, I said, heck no, their new. Well, after removing I found the problem.
To correct it, I used non-hardening gasket sealer and did the gasket and the valve cover. I sat these down on the workbench with some weight on them to help seat the gasket to the cover. I waited for about 20 minutes and then installed using RTV to the head and torqued to spec. It hasn't leaked yet.

Replace the valve cover gasket so they are not the contributor to the leak.

Them move from there.

I bet you it is the valve covers if they have been loose. Clean the surfaces before you install the new gaskets seeing they will be very grimy being loose.