OK, I know the ins/outs of intake manifold oil leak repair. In fact, I did it myself 1.5 yrs ago. Guess what? Now its leaking again. I was very careful in doing it correctly and taking my time. The front & rear RTV seals are leaking.
What is the best RTV to use for this application?
I used Permatex HiTemp Copper RTV last time and its leaking again. STuff just seems so slippery it doesn't 'bite' to the metal. Oil seems to seep past. Anyone use some other stuff for this that worked really well? Long term results?

Oh, whats up with the search function? I only get 4-5 returns for some of the simplist searches.

 

That Ultra Blue stuff in the silver tube has never let me down, it works very well.

 

Did you re-torque the bolts after you had run the car a few thousand miles? I didn't, and based on what people have said on this board I am convinced that's the reason it's leaking again(about 20k miles later).

 

I've starting using "Ultra Black" sealer now and have never had the problems I used to have with the slippery blue and clear stuff. Should be able to find it at any auto store, its in a black tube.
Used it on my timing cover, which used to always leak after removing it on my GN, never leaked again in 3 years.
Use it on all my valve covers, and no leaks yet after being on there for 2 years. I just did the intake on the LT1 last spring, so far no more leaks.
This stuff doesn't harden, but its not slippery like the silicon blue stuff and is more difficult to scrap off, so I guess thats why it works better.

 

Ultra Blue sounds promising. I believe I'll have to check that stuff out when I hit the parts store.

 

This is what you want to do.

Grab a punch and a hammer and start to dimple the rails were the silicon goes. This will give it something to grip onto.

Remember, you must let it sit for 24 hours, before starting up the car. Shouldn't have any leaks after that.

Black silicon is all you need.


Neal

 

Here's a helpful link if doing it yourself:
http://www.geocities.com/MotorCity/Downs/4013/ol.html

 

I use the Ultra-Copper with a roughened surface (just some 80 grit sandpaper on both surfaces) and a closed-cell-silicone sheet foam gasket probably .200 thick when un-compressed, and flattens right down to almost nothing when compressed. I put some RTV on both sides and sandwhich it down, never had a problem since.

I've done it with just the UC and roughened surface and it worked fine on a friends car with the same problem.

 

I second the "re-torque" motion. I didn't re-torque my bolts and it started leaking again about 20k later. I got a good seal in the back near the EGR pipe (suprisingly), but it's leaking out the front.

 

Permatex GREY RTV is the BEST stuff EVER. It will hold up longer and better than ANY other brand or color. Yes its an IMPORT sealant, butthe guy who built my engine ahas built engines for 20 years. He says the GREY RTV is the only kind that NEVER leaks when applied properly. It was used on my engine and Intake when I rebuilt it and it doesnt leak a DROP anywhere

 

Yep....ultra grey will hold....also make sure and clean the surface real good with some acetone or denatured alcohol

 

GM "GMS" sealer. The same stuff they use and sell at the dealerships.

Frank

 

Thats good stuff too....hard as heck to clean off though.

 

LOL...2 word...Brake Kleen!

Frank