I also use the "white" permatex thread sealer. Its in a tube

The oil sender could be fine as is but given how hard it is to see back there with everything on the motor, IMHO, always good to confirm it was not the cause by removing and putting on new thread sealer at this stage of the repair

I see many, and it looks like the shbox pix, uses "The Right Stuff" RTV. I have always used the Black "ultra" with no leak results as it says it is for oil & high temp. Your call on which to use but if The Right Stuff before and it did leak I would use the black ultra

It says on the tube how long to let it "set up" before assembly so you can certainly follow whatever product you are using directions

 

All the parts are in, and per your suggestion I read the Permatex instructions... It says to place the bead, then while wet, place the parts together, tightening bolts by hand until there is a small amount of squish on the bead. It then says to allow 1 hour before torquing, then 24 hours to cure.

If this is the proper method, I need to start reading all of the things I buy as this is way off what I am used to doing.

 

yeah Drew I am also guilty of not following what a particular product says how to use it.

Given this has been a problematic leak for you I would do as the instructions say on the 1 hr after "slight" pressure is made securing the intake

I read it as Pematex wants both surfaces to be mated while RTV is "wet" so they adhere to the surface optimally. Then allow the RTV that is in-between the two surfaces to cure some, 1 hr, before final TQ sequences

Admittingly I have only just let it cure first about 10 min then install manifold then TQ sequence then let cure 24 hrs. Has worked for me but if I had sealing failures like you I would follow the directions of the product to the letter

 

Better safe than sorry since this will be the second time. Admittedly, my first go I had little real idea (other than the final torque number and sequence), and thought I had it all sorted out the last time. I am still on the fence as to if I want to dimple the rear China wall. I think it could help, but it would make cleaning the mating surfaces a nightmare should I ever take the intake off again...

 

IMHO you should not need to dimple the china wall or intake

 

Everything hurts

I got the intake apart and back together and test ran the engine for another minute with no oil on the ground! From the cleanup process, I did have RTV up the heads onto the gaskets, so my best guess as to what happened is the lack of waiting. This time I gave about 10 minutes for the RTV to set up, then placed the intake manifold giving it a full hour with just the weight of the manifold. I also noticed the banjo gaskets on the steam pipe were shot and replaced those ($9 each seems like highway robbery).

Anyhow, nothing is ever easy, the poly mounts really make getting the transmission in a challenge. With zero play on the engine, getting the transmission to line up took me about an hour of maneuvering things back and forth. I was able to get the challenge bolt on pretty easily by hand threading it in, then using a 1/4 in socket, universal joint and a couple extensions. The rest of the bolts were easy. I couldn't find the bell housing bolts in town, but replaced the transmission to bell housing bolts with 12pt ARP, I really think they make working in tight spaces easier.

The biggest challenge though was unexpected: the transmission cross member. I had bought a BMR replacement earlier in the year and when trying to install it last night, my custom exhaust is in the way. I have cutouts behind the headers facing inward that didn't clear the torque arm relocation plate. I cut out a fair amount of what was in the way, but still have a bit to go (working with a Dremel for the thickness of steal is slow work), but I think that I will be able to make it work. I was going to just put the stock mount back on temporarily, but found the stud to be too long to go in with the transmission installed, and there was a 0% chance that I was taking the transmission out again for a temporary fix.

I hope to have more good news to come, but I am feeling pretty hopeful with the ground still being clean. Thank you for all of the advice and guidance!

 

Good to hear Drew.

Maybe Santa will get you a angle grinder/cut-off tool :-)
Harbor Freight special

 

This has nothing to do with the rear main seal, but it appears the rear of my intake may be leaking. I’m pretty sure it wasn’t leaking when we “fixed” this leak years ago, but it doesn’t seem to have lasted for very many miles. The rear of the intake is “wet” on the passenger side and I have some oil on the floor just in front of the rear axle. I haven’t checked anything else, but I assume this is the source. I hate leaks, but I’m not too fired up about removing the intake, and everything that comes with it, just to “theoretically” take care of an oil leak.

Do people ever use The Right Stuff on the intake. I used Permatex copper.

 

Active thread on another site, discussing intake manifold sealing:

Recomended intake sealant?

 

I honestly think my issue was procedural. I let the RTV set up some before setting the intake, then immediately torqued it down. The directions on the ultra black clearly indicate that you should mate the surfaces while wet, then hand tighten bolts. Allow the pieces to cure for 1 hour, then torque.

So far so good for me. Outside of oil leaks being dirty and annoying, this one killed my clutch. There are two small threaded holes on the portion of the block that mates to the bel housing. My intake leak was going directly into the passenger side hole causing the flywheel to fling oil over every inch of the clutch and pressure plate.

 

Thanks for the link, Injuneer.

It’s probably been 12-13 years since the intake was removed and re-installed on my car. I’m not sure why we went with Permatex Copper vs the Black. The car has been run quite a bit subsequent to that, but it's only been driven the last 2-3 years for about 700 miles. I’m pretty sure it did not leak for a while, but it sure seems like it may be leaking now. It’s obviously leaking somewhere. If I were to tear into the engine at this point I would probably want to do heads etc., which sounds like a 20 year project, which would put me in my mid 70’s, and I’ve never done anything like that in my life.

Sorry for the hijack. It was at least somewhat on topic of what was being discussed towards the end of the thread.

 

Mine was done in 2000 when the stroker was built. Never leaked. The shop used the Permatex Ultra Copper. The copper has a higher temperature resistance than black. It's actually labeled as:

Permatex® Ultra Copper® Maximum Temperature RTV Silicone Gasket Maker

Permatex seems to indicate black has a higher oil resistance.

Permatex® Ultra Black® Maximum Oil Resistance RTV Silicone Gasket Maker

In the early days (mid to late 1990's) of the LT1 intake manifold leaks, one theory was that the manifold leak was caused by the proximity of the EGR riser tube, and its connection on the passenger side of the intake manifold. Passenger side seemed to be where the leak developed. I think that may have been what caused some to prefer copper over black.

 

I’m guessing we probably used copper due to the temp rating. The passenger side appears to be where mine is leaking. I’ve removed EGR, which I believe would have included that riser tube. I’m pretty sure we plugged that connection on the rear of the intake manifold. Our intake manifold install procedures probably weren’t perfect, but we tried to follow best practices. I do think we let the RTV set up for a few minutes before putting the manifold back on. That seemed to be the prevailing wisdom at the time. It’s a lot of work to address an oil leak and everything has to be put back together to see if it’s still leaking/not leaking. I guess it is what it is.

I just took a look at the Permatex site and they have introduced a couple of new products. I wonder if the Optimum products would be of any benefit in this application. Dissimilar metals are mentioned for the new Optimum Black.

Permatex Product Comparison

 

My $.02 on why I use the ultra black is it is more impervious to oil than the other types....and since "oil" is what leaks from the intake @ china walls I use it and have not had to "repeat" the process after removing intake for H/C builds. YMMV

Many people do swear by the Copper aka "Right Stuff" so whatever has previously worked than continue to use

Surface prep and mating surface trueness are a factor on any RTV application so if those points are not confirmed RTV fail of any type likely occurs

IIRC the GM sealant was grey although IDK what type of Permatex it is

 

After a few days of driving around with no leaks, I found a few drops of oil on the floor yesterday. The drops we below the ABS pump, and seemed like an odd place, but I ended up finding some clinging on to the rear of the engine and transmission as well. From what I can tell, it looks like it is coming from the drive side rear of the pan. I pulled off the dust shield from the bell housing and below the RMS is bone dry. I am also seeing a small amount of oil under the starter. I took a white rag and blotted all around the back of the intake and could not find anything wet, so at least that part is promising. I think I am going to try the pan gasket one final time employing what I learned about the RTV from the intake manifold, giving the pan 1 hour on the RTV with hand tighten the bolts, then allow the pan to cure for an hour before final torque. I also think I am going to drop the cross member so I can take the pan off, verify the rail flatness, and have an easier time with re-installation. I thought that the big hurdle was going to be getting it on the road for a day, and after no leaks, I was starting to breath easily, but it kicked me in the nuts as usual.