Help! Major oil leak, new engine?

Hello again,

I've been a lurker for a while and love the information given here. Need your help and advice. I have a major oil leak. I have an 89' s-10 Blazer, 4x4, manual, 2.8. The leak is coming from high up on the back of the engine. I took it to a couple of places and they told me it was the rear main oil seal. Well I finally got a friend to help me over the last week and we dropped the transmission, replace the rear main oil seal, while we were there we replace the freeze plugs and clutch as well. The freeze plugs were leaking and the clutch was soaked with oil. This thing has been leaking for a while. Well after putting it all back together the leak was still there. OK, so it wasn't the rear main oil seal. So we figure must be the intake manifold gasket. Take apart the top of the engine, replace the seals, put it back together and leak is still there. I'm thinking the block must be cracked or something simular. What is your opinion??

Now to the next question. Replacing the engine. I have decided I am not getting rid of the truck, there is nothing wrong with anything else, I just don't think it's worth trashing. What kind of engine should I get and where? I thought I read that I could upgrade to a 3.x, I thought like a 3.2 or something but can't remember the exact number, without having to change anything else. True or not?? When buying an engine should I buy one with everything on it, like a turn key motor I believe it's called or should I just buy the block and transfer everything from my motor to the new one?

Thanks for all your help and advice.

IF the 2.8 is similar in design to the small block V8 , the oil pressure sending unit is on the back of the engine under the distributor and it may have an oil line running thru the firewall to the dash , I don't know what year GM swicthed to electronic . Mine was a brass fitting on a 77 year full size and it was leaking there . I have a mini with the 4.3 , an 89 now but can"t help you with the swap options. Good luck Robert

I assume that when you did the intake gasket, you did the gasket around the distributer. There are also oil galley plugs on the rear of the motor above and to the side of the rear main. I have seen these leak and it looks like the rear main leaking because the flywheel slings the oil around.

The 2.8L was ungraded to a 3.1L motor then to a 3.4L but be careful because you can only use one from a rear wheel drive vehicle because of the bolt holes for the motor mounts. I think the Camaro and Firebird V6 engines will work. You can't go to the 4.3L without changing the transmission (different bolt pattern).

I assume that when you did the intake gasket, you did the gasket around the distributer. There are also oil galley plugs on the rear of the motor above and to the side of the rear main. I have seen these leak and it looks like the rear main leaking because the flywheel slings the oil around.

The 2.8L was ungraded to a 3.1L motor then to a 3.4L but be careful because you can only use one from a rear wheel drive vehicle because of the bolt holes for the motor mounts. I think the Camaro and Firebird V6 engines will work. You can't go to the 4.3L without changing the transmission (different bolt pattern).

So I have a question for you. Keep in mind that I do not claim to be a mechanic by any means. I have a friend that is a decent back yard mechanic that is helping me with this. Now about the seal around the distributor, I do not remember there being one when we took it off and do not believe one was used when putting it back on. When I bought the intake manifold gasket set it came with a small, maybe 1 inch in diameter maybe larger, but it came with a small rubber o-ring. What is this for? Was this supposed to go around the distributor. When we took everything off we noticed a bunch of oil right there at the distributor, just figured it was the manifold seal.

Question about the 3.4 engine, the ones I see for sale all seem to be for automatics. Do they have manual's?

The oil galley plugs, I assume these are not on the back of the block where the freeze plugs are, I do not remember there being anything else for us to replace when we were there. Are they higher up on the engine?

Sounds very much like either the distributor seal/gasket or oil pressure sending unit.....easiest way to find it is to degrease the back of the engine and run it to find the leak.....

There should be an O ring around the distributor housing. With age, they will harden and crack. Since it is under pressure, it will leak.

The oil galley plugs are higher up, they're lined up with the valve lifters. That's how they drill the oil passage to feed the lifters.

The 3.4L motors did come with manual trans in the camaros. Since they are all multiport, you would have to use the computer and harness. Also the Camaros have a anti-theft tied into the computer.

I don't think any motor other than another 2.8L would be an easy bolt in. The motors from the camaros use multiport as opposed to the blazer TBI & CPI. The intakes won't interchange. I don't know if you could switch cylinder heads and intake.

Sending unit on back of block or does it have the remote oil filter mounted away from the block up in the drivers fender like the 4.3. The unit on the block goes bad and spews oil every where. O-rings and gaskets cost $4.

How about the valve cover gaskets?

Also, go buy the UV dye you can put in your oil and you can use a UV light and trace down where the leak is coming from.

Well, I got the leak fixed. What an tremendous amount of work for what ended up being a 30 minute fix. The problem was that I didn't replace the distributor seal. After replacing that I was golden. So it ended up taking me about 7 days of work, 9 days of time, replaced the clutch, freeze plugs, rear main oil seal and damn near every gasket and seal in the engine. This thing better not give me any problems now. Thanks again everyone.

[QUOTE=rjeffas]Well, I got the leak fixed. What an tremendous amount of work for what ended up being a 30 minute fix. The problem was that I didn't replace the distributor seal. After replacing that I was golden. So it ended up taking me about 7 days of work, 9 days of time, replaced the clutch, freeze plugs, rear main oil seal and damn near every gasket and seal in the engine. This thing better not give me any problems now. Thanks again

WOW. that right there is why I always look at the cheapest little fixes first and work my way up.

WOW. that right there is why I always look at the cheapest little fixes first and work my way up.

Boy that's the truth. I made the hudge mistake of actually thinking that the three repair shops I took it to before I decided to work on it myself would have been correct in what they said was the problem. Amazing that all of them were wrong, and all of them were saying it was the rear main seal. Funny how that is one of the most expensive repairs to do... Well this last week and a half has been a hudge learning experience for me.