"Anybody seen this?"

[sidthirteen]

As some of you know,I had to put my truck together pretty quick to get to work. I've been fine tuning it in the mornings before I go to work and has been running like champ until this week when I started to notice a few oil drops on the floor on Monday. At first I check the vavle covers and they seemed okay. By Wednesday, I had more oil on the floor and went ahead and Checked the oil pressure line fitting and was able to get about 2 turns until tight. Everything seemed okay, until last night going home from work. I was at a stop light when all of a sudden, there was smoke coming out from underneath the truck! Got it home and looked under neath and found oil sprayed all underneath the frame all the way back to the rea coils!! This morning, I got up and started to look around for this damn leak!! This what I found.......

This is what I was looking at this morning.(kinda looks like new trailing arm, right? But no, their showered with oil!!!)

Out comes the intake manifold and I found the problem.....

Anybody ever see this happen to the rear intake gasket?

Got the new intake gasket kit and gonna do it tommorrow... Have a good weekend everybody!!!

[austex66]

Dam that sux, but fast diagnos! I notice my intake leaks in the back, but nothing like that.........yet

[sidthirteen]

Yeah, I had to put an inspection mirror to see behind the distibutor. That's when I found it spewin' from back there.

[Imperial Kustom]

Intake end gaskets are pretty much a joke and are notorious for pushing out. Get some Permatex Ultra Black or Aluminum RTV, put on your manifold gaskets (silicone both sides of the gasket around the water passages, front and rear), and then run a big bead of silicone along the block ends. Make sure the surfaces are clean and dry! Set the manifold on and then squeegee the excess silicone with your finger, making sure that not only are you cleaning off what squeezed out, but pushing it back in too.

[sidthirteen]

That's exactly what I'm gonna do this time around. Thanks Imperial!!

[Tx Firefighter]

I was working as a GM tech in 94. They published a GM bulletin to all the dealerships saying to never use the rubber end gaskets anymore. Just lay a 1/4 inch bead of silicone instead. That is straight from the general himself.

Apparently, the warranty claims for those things splitting and leaking got too frequent.

[Hipper]

dido on the throw the end gaskets in the trash. I like ultra black or ultra gray. And TX Firefighter is right on the GM Bulletin, I have been turning wrenchs for 21 years and 10 of those at a GM dealership.And yes put a thin coat on the gaskets around the water ports.

[sidthirteen]

Thanks TX for info!! Would the "Black Hi- Temp" RTV work?

[Captainfab]

Is it possible you could have built up pressure in the crankcase? Do you have your pcv valve in the valve cover on one side and a breather on the other side?

Yes the black RTV silicone should be fine.

[sidthirteen]

Cool! Thanks HIPPER!!

[sidthirteen]

Originally Posted by Captainfab

Is it possible you could have built up pressure in the crankcase? Do you have your pcv valve in the valve cover on one side and a breather on the other side?

Yes the black RTV silicone should be fine.

At first I did have the pcv on one side and breather on the other, but I took the pcv out and put a second breather on. It looked like it was suckin' oil through the pcv line.....

[Fred T]

Ultra black, blue or grey will work. Just don't use the red or copper. I lay down a bead, then set the manifold on and line it up. Before snugging down the bolts get your inspection mirror out and check the back side. It's a lot easier to fix before the rtv sets.

Also, too much sealant is not good. About a 1/4" bead usually works.

[sidthirteen]

Originally Posted by Fred T

Ultra black, blue or grey will work. Just don't use the red or copper. I lay down a bead, then set the manifold on and line it up. Before snugging down the bolts get your inspection mirror out and check the back side. It's a lot easier to fix before the rtv sets.

Also, too much sealant is not good. About a 1/4" bead usually works.

Right on Fred T! Thanks!!

[1966gmc]

And that is the reason I never used them rubber end gaskets. RTV is muh best friend for intake jobs

[bird7263]

I had the exact same thing happen on my 67 right after I bought and drove it home.. oil was blowing out the back gasket and dumping on the headers pipes.. Smoked like a B.. And it left puddles underneath.. I knew exatly what the problem was.. I did the same as you right off the bat.. I like everybody else I use the ultra black.. A trick that we have been doing for about 10 years is, take a ball pean hammer and tap the front and back edges and make it a littte ruff. This allows the ultra black to find a good home, kinda like when you sand then paint. We do this on all of our late model stock cars.. I have seen dozens of guys do this on the race track.. Has never failed me or any body I have ever raced with.

[sidthirteen]

Thanks BIRD!! I'll try that on my next motor.