I've been trying to diagnose a mild oil leak issue for a while on my 2002 4x4 blazer.
Today I cleaned her up, changed the oil, did a test drive, and found that the leak appeared to be coming from the front where the harmonic balancer is.


I notice a white caulking type of substance at about the 4-o-clock position on this housing that goes to the harmonic balancer. There isn't however any type of chalking or seal near the 6-o-clock position and that is where it seems to be leaking.

Instead of pulling this off and replacing the seal, is there a spray-on substance or type of caulking that I could just apply on top of it how it is without taking anything apart?

 

I think that you'll run into the problem of getting it clean enough to stick. How quick is the leak?

 

About 2 pints maybe every 1,000 miles.

I change the oil every 3,500 miles and I usually need to top it off a bit in between changes to bring the level back to the middle point on the stick.

Not a tremendous amount of oil, but enough to make a huge mess on the garage floor.



The top photo is the leak over night without cardboard to catch it after a 30 minute drive.

The bottom photo is the cardboard catching the leak for about 3 months.

 

I haven't had any experience in engine seals, so not sure if theres any worth it and that will last.

 

That won't stop it. That area is soaked in hot liquid oil thrashing around as the crank turns. Time to pull the plastic front cover and oil pan and replace the cover and pan gasket. Change the timing chain also.

 

This. The seal in the cover isn't replaceable, and the cover isn't reusable once you remove it. Buy an OEM cover instead of a cheap aftermarket one. And if you want to be sure it doesn't leak, you should probably replace the harmonic balancer as well.

 

There is this product.

I had tried it and I got mixed results. I suspect because I did not get it to where I needed it (behind some brackets near the heads).

It might be worth trying as it is so easy to do.



https://www.permatex.com/?s=82099

 

Oh jeeezzz
I found the actual oil leak.



Seems to be rear-main seal I'm guessing.
Damn...

I haven't even driven her today after the oil change or ran the engine, and I found a puddle of oil on the floor when I came out to check on things.

 

I have a small leak from there too but I'm pretty sure it is because the oil pan bolts/nuts are loose. I snugged them up (to spec) last year and I think it helped. However, I suspect they are loose again. I think it was Error_401 who said it took him a couple tries by him to keep the nuts in place. If I remember correctly he had to try to get the studs super clean and then used thread locker on them.

The next time I'm under there, I'm planning on snugging up the nuts and bolts again and then adding Nylok nuts to keep the rear nuts in place.

I don't think this oil pan for a 4.3L is for our Blazers but it does show the rear nuts for the oil pan that are on either side of the rear main seal.

P.S. I always wondered if there were supposed to be plugs in those holes. And you still have yours!

https://www.diyforums.net/after-all-.....-165169.html

 

Don't jump straight to the rear main right away. The very back of the lower intake manifold gasket where it meats the block on the 4.3 has a tendency to spring a leak, run down the back of the block, and give the illusion of a rear main seal gone bad. Not saying that's what it is for sure in your case, but it would not be the first time.