Hi i am a new owner of a 1987 2.8l chevy blazer 5speed 4wd. so heres the story i bought the blazer with a motor that was knoking really bad and tht motor blew so i pulled a motor out. I put in a 2.8l out of a 1993 s10 that i knew ran and it didnt have an oil leack (it came out of a freinds wrecked truck). i put the New s10 motor into my blazer and it runs but after 5 min or so, of running it startes to drip oil where the transmisson and bellhousing meet i was told it might be the rear main seal or the imput shaft seal has any one else had this problem and know exactly what it is PLease need help thanks cody

 

yep,sounds like the rear seal. OR could be the remote oil filter that runs down into the adapter on the block(if you have a remote filter). when it leaks it finds its way under the trans and makes it look like a rear seal. it happened to mine.

 

ok thanks ill check the remote oil filter tommorow if i do have one im not sure

 

I doubt a '93 2.8L would have a remote filter. I believe the filter on a '93 2.8L is on the back of the block on the left side. I had a '92 S-10 pickup with the 2.8L and the filter was in the place previously described. That truck had a very similar oil leak to what you describe. I just added oil regularly and sold the truck to my sister.

 

Check the oil pressure sender too. It's right next to the filter. Sounds like a main seal to me. Been there, done that.By the way the real early 2.8s (like the 83) were inferior to the later models (like your 87). They beefed up the later models a bit but if it runs, go for it. I think you're going to be pulling the tranny or the motor to fix it. Is it oil or trans fluid/gear oil that's leaking. That's what I would check first.

 

thanks guys i figured it out it was coming from the distributor and running down the top of the bell housing making it look like the rear main but just a lil o ring on the distributer