Basically, my question is... are there any trans-engine bolt holes that go through the block that would leak oil if I didnt put a bolt in them?

I just put in a 2 piece RMS 350 block, the year of the block is (IIRC) 1971, and it's the 010 casting.

Basically, I've got the motor running but there's a big oil leak from the rear of the block as best I can tell.

I thought that it was the rear of the valve cover on the driver side, so I replaced it, but the leak is still there.

It's a big oil leak, it drips oil pretty bad, about 1/4 a quart if I start the car for about 10 seconds.

Some of the possibilities that Im thinking that it could be are:

back of the intake that I put on could be leaking, but I used plenty of the "goo", but not too much, plus it's not TOO wet there.

coming from the block itself.

I've only got 2 bolts connecting the trans to the engine right now because I lost the other of them. I do plan to get these bolts, but I was hoping to lower the trans and do a bunch of work to it including putting the other bolts in at the same time, so if I dont have to right now I'd rather hold off on it (rest assured that I WILL do it though).

 

Right behind the intake, near the distributor, there is an oil passage that has about a 1/4" opening. I had to cap it off on my new motor because apparently the L98 used it to do something with. I'm not familiar with the flat tappet blocks but I'd imagine there's gotta be a hole not plugged somewhere in the back.

 

"Freeze plug" not installed behind the cam.

 

you mean where that copper "tee" is that is pictured on the back of your engine?

I'll have to feel around there though, thanks for the idea, keep 'em coming lol.

 

valve covers
intake
distributor
oil pressure sender <---- check this!

 

I currently have the hole for the oil pressure sender plugged up since I cant find the copper "tee" that screws into the block, that lets the oil pressure sender connect. I do have one for a manual oil pressure reader, but I dont have a manual oil pressure reader to go w/ it.

I've also checked there a few times now, and it doesnt seem to be coming from there since the bolt is only wet at the bottom of it.

I also dont have a dipstick tube, so I have a bolt plugging that up as well, and it looks similar.

 

rear mian seal, is the flywheel wet or inside the bell housing wet?

 

I hope you're wrong about the rear main seal, because I dont want to change oil pan gaskets LOL... plus it's apparently a brand new rubber one.

The trail of oil SEEMS to come from the driver's side, it trails from around the bellhousing... My guess is it's something on the top-end.

Guess the best way to tell is to get the little "T" connector so I can plug the oil pressure sending unit in, and see if that's where it's coming from... I'm not 100% sure it's sealing up right.. since I dont have the right thread count bolt in the hole, it could just be sending the oil past in a small squirt or stream there.

oh and Token, there was a bolt hole right behind the oil pressure sending unit hole, is that what you're talking about? I shoved a bolt in there and will try and start the car up and see if that fixed it or not. Thanks for the idea too

 

That's my vacuum line for power brakes, but what I'm referring to is a little 1/4" square-head plug that screws into the center of the top of the block, right behind the intake manifold. I can get a picture tomorrow if you don't get anywhere with it

 

Actually I have a picture of what I'm talking about already. I circled it for you.

 

There is a fitting above the oil filter that they sometimes put a oil pressure sending unit in. Is the oil filter tight?

 

Thanks for the picture Token, it helped.

I ended up going to work and grabbing the right thread count bolt and I stuck that in there and it slowed the leak down tremendously. I'll use some thread tape on the sending unit tee when I get it, and that should cover the rest of the bases

Thanks for the help everyone

 

high five man, I knew I was right from the first you described it I was confused at what my L98 had that thing for but the LO3 was capped off... so I just capped it back off.