I have an oil leak somewhere in the rear of the motor and having trouble figuring out where its coming from.

The front of the motor is totally dry but it looks as if the leak may be coming from in between the motor and trans. The starter also get oil on it and the bolts have a fair amount on them. As a result, I am getting oil all over the bottom of the car towards the rear.

What seals besides the rear main are in between the trans and the motor?

Anything else I should look at in the rear of the motor?

Rear of the intake manifold is also dry so that's not the cause. My clutch is not slipping so it doesn't appear oil is getting on the clutch.

-Brian

 

Most likely the rear main seal, but check the oil pan as well to make sure that isnt leaking. rear main and oil pan seem most common and if its coming from in between the trans and motor than it is only the rear main. Shoot a bunch of brake cleaner or engine degreaser to wash away all the oil that has leaked and then watch for where the leak comes from to pin point it and make sure it is only 1 seal, because most of the time you can replace the oil pan gasket and the rear main seal at the same time, not sure if you can replace the oil pan gasket without removing the trans.

 

if it were the rear main you would mostlikely be having issues with your clutch, mine was leaking from the back of the intake manifold where it meets the block, but it could also be leaking from the valvecovers or the sending unit

 

I'm betting it is the rear of the intake or valve cover.

 

I replaced the intake manifold and it better not be from back there again. I can't seem to get this thing to stop leaking. It's been done 3 separate times. I will check the oil pan and the sending unit just to make sure. The valve cover gaskets were replaced but again I'll check to see if they are leaking again.

Thanks for the help.

-Brian

 

when you replaced the intake manifold were you sure to seal it up good with some rtv

 

Yea I read all the tutorials and did all the tricks. Only thing that may have messed the bead of the silicone on the rear is that hard pipe in the back. I still can't believe I'm having this issue and my hands don't fit back there to feel for a leak. Guess I need to find someone with smaller arms.

-Brian

 

I have a pretty decent rear main leak and i don't have any issues with the clutch.. yet. what do you notice in the clutch from a rear main leak?

 

I 2nd the behind the intake leak.

 

I'm getting ready to try my third attempt to get the back of my intake to stop leaking on my 93Z. I've read all the threads and I think I will try using a flat trans gasket to line the back of the block. Anybody tried this??

 

I wouldn't. A good RTV will seal just fine.

 

You know there are scores of threads on this subject, but many people still have this problem. Some people just accept this as part of owning an LT1. I know some people have wrote in saying that they have no leak with just using RTV, but I bet the majority of owners still have a leak and honestly there has to be a better way!! I never had any where near this much trouble with Gen 1 motors, and they all run a seal back there.

 

Well, good luck if you try the seal. I have used high temp RTV on my 94 and my GF's 95, and not a leak to be found.

 

I would put the car up on a lift ,get a flashlight,and see where the oil is coming from.I think you can get a gasket that fills the void for intake manifold leak.Hope this helps.

 

I would be very interested to know where a gasket is available for the LT1. I checked with my local auto parts for one and the Fel Pro one did not include a rear gasket. No gasket included for the rear part of the intake. I thought I might try using some fel pro tranny gasket material that is rubber, thin and pretty tough. I know the intake and block were intended to fit flush, but the tolerances must be off.