this is the 2nd time on my 97 ws6 im gonna have to take the intake manifold off to fix the back gasket to stop the oil leak. is there some kind of fix or mod i can do to prevent this from happening again? i was sick of the intake manfiod the first time...

 

Either you didn't apply the RTV right the first time, or you didn't give it time to cure after the first fix.

Them leaking is a known issue on the LT1.

I've done about 6 or 7 LT1 intake manifolds now and never had one leak on me. Usually did them due to cam swaps, but same idea.

 

guess i gotta do it again.. i let that thing sit over nite.. the reason why i did it the first time, cuz it started leaking out of no where, and now its doing it again.

 

never had this prob, dont know what everyone is complaining about, I have a 96, i use alot of silicon back there, i personally think its the way you guys are installing your intakes, dont slide them on, with limited space theres still room to lift it over the engine and drop it and Id recommend letting it sit before you fire it up, ive always done it this way and never a problem.

 

someone said something about the EGR tube being metal and it gets really hot and melts that rear seal? is that possible?

doesnt make sense to me, i changed it the first time cuz it started leaking (no work on intake manifold previous) fixed it and its leaking again. hopefully its installer errror and not something stupid. i got enogh stupid crap with the steering and alignment where i cant even drive it, now its non drivable and leaking oil. how great can life get.

 

You can drop the engine, and weld the intake to the block Vindiesel style,

or you can use copper RTV sealer, and make your you bend the exahust tube away from the rear of the intake so that it's not touching... just another design flaw on the good ol' LT-1.

 

maybe try a gasket material called the "right stuff" this time.

 

i used "right stuff" and it aint right. IM gonna go with the copper RTV sealer cuz ive seen ppl use them on there headers, and if they can hold up header heat then im sure it will hold up the heat from that stupid LT1 egr tube. The thing that questions me is will copper RTV hold up against oil?

 

ROCK ON!

 

Apply a decent amount of RTV on the back of the intake and the front as well. Make sure it covers the whole area even dab a little on the edges where oil could seep out.

when installing the intake make sure u can drop it right on u dont want the intake to move around too much.

I was told to let the RTV cure for about 24 hours. If u dont let it cure the intake will leak again


Good luck , its not an entirely hard job, but everything think on these cars is a pain in the ****.

 

I've done this a bunch of times, and "the right stuff" works really good. It's stickier than RTV and a gob of it is less likely to break off. I swear by that stuff for the intake leaks - and the cars that I work on don't have ANY leaks even with synthetic oil. Now I'm not saying the other copper, blue, black, grey, whatever colors of rtv don't work, but I've found this stuff to be better. You want to get a little of it around the ends of the intake gaskets which, incidently, I use coppercoat on.

One other trick I use is to dremel a trough in the back of the sealing suface of the manifold. That helps the bead from slithering out of there once it cures.

 

No it's not. I explored this some years ago and talked to many GM service people and they all agree the reasoning behind the leak originally is due to the factory not applying enough sealant on the block. I also found the intake bolts will become loose after a few heat cycles working the RTV seal loose from the intake expanding/contracting. Throw that in w/ not allowing the sealant to cure or if the manifold wasn't placed on the sealant w/out moving it and you may find yourself with some leakage issues. It would be a good idea after running the car for about a week to go back and check the intake bolts. I always found mine to loosen up.

 

If you can't find Right Stuff, there is another premium sealer available. I went looking for Right Stuff, and the old Napa guy recommended Permatex Ultra Black instead.

It bonds well, and is very stretchy/sqishy when cured, but tough. I put a couple pieces of iron strapping together with a bead, and can't pry them apart. Comes in a tube or pressurized dispenser can. At 25 bucks a can, it better work great on my intake, hopefully this weekend. So far I've only used it to attach a rubber hose to a 2-stroke expansion chamber muffler, but that is hot and very oily, and the stuff is still stuck on good.

 

Same problem 3 times on a 97ss. Useing the permatex Ultra-black, and set-up 1 + hour before intake install. Also, I roughed up the block china-wall and used brake cleaner. Modded the intake manifold. Machined a small groove to hold the RTV. No leaks. B.

 

I used Permatex Ultra Copper and let it sit for about two days post installation. We'll see how it holds up, but it didn't appear to be leaking during a very limited amount of time that I had my car running afterwards.