Blowing out EGR gasket

[GTRS Fiero]

The gasket between the EGR mount block and the Y-pipe keeps blowing out.  Apparently, there is some pressure in there, but the cat and muffler both test OK.

The cause appears to be some scratches on the Y-pipe mating surface.  Attempts to file the surface flat have failed to change the result.  Ultimately, the gasket blows after about 100 miles of driving.

Any ideas on a fix?

[scottb]

Hitemp red silicone

[GTRS Fiero]

We tried that.  It melted and ended up in bits all over.

[Fierofool]

I don't understand why they are blowing so frequently.  I've not heard of anyone else having the problem, so it's probably not the adapter or the gasket.  Do you have the graphite gasket or the cardboard gasket? 

You might be able to mix up a good sized batch of a liquid steel or JBWeld and completely coat the base.  While it's still malleable, install your graphite impregnated gasket and adapter and torque it down to let it cure for a couple of days.  Once it's cured well, install the EGR valve. 

Just wondering if a piece of non-stick foil placed between the JBWeld and gasket with the non-stick side against the filler would release after cure. 

[TopNotch]

Get some plasti-gauge and arrange pieces of it around the Y-pipe mounting surface, and bolt the block on without a gasket. Remove it and see if the plasti-gauge reveals a bad spot.

[GTRS Fiero]

I can see the marks.

I like the JBWeld idea.  Very done with this.  Not sure if JBWeld will withstand the prolonged high temps, though.

[Fierofool]

That was why I suggested a liquid steel.  JBWeld makes a product called Extreme Heat Epoxy Adhesive.  It's good for up to 2400 f.  It has a working life of about 1 hour.  I found it listed at Graingers.  A 3 oz. Jar was $6.75. 

If you have an anvil or a piece of flat rigid steel, I'd try a small dab sandwiched between 2 pieces of non-stick foil to see if it sticks when cured.  If not, then I'd give it a try the way I described above.  Of course, you could also use a piece of parchment paper like used for baking, instead.  That way when it's cured, you could just burn off the paper if it sticks. 

[GTRS Fiero]

How do I prevent some from restricting the tube around the hole, when torquing the adapter?

[Fierofool]

You might need to remove everything and do a cleanup. Dremel Tool or such. 

[GTRS Fiero]

Joyful.

[GTRS Fiero]

Ralph, since you asked, here is an image of TFS' EGR gasket:



Apparently, it's compressed graphite.

[Wreck It Ralph]

I can see two options fir a permanent fix. Both require you to remove the crossover pipe. First is they to sand or plane it flat. Topnotch is right with the plastigauge. It will reveal the bad spot. Best to fix it right.

The other way is to carefully liquid weld it together. With the pipe off you can control it better.

You could also see if a welder can stick them together but if I remember the adapter is pot metal and exhaust of course is steel.

I know you say the cat is good. #1 do you have to run a cat in your state? #2 how was it tested? There are two was to test it, back pressure gauge or temperature check. You can get the back pressure gauge as a loner tool from most part stores but they are cheap. I don’t recall what pressure is acceptable but I’m sure it’s a google search away. But you said it’s 100 miles to make it happen. You were running rich which will overheat and clog a cat. Temperature test is the best. The temperature on the intake of the cat should be about 100°F colder then the outlet.

[GTRS Fiero]

So, no more permatex?

[Wreck It Ralph]

Permatex is a good bandaid for now but I’d want to get to the root cause. If it’s a cat problem then you will cause other problems by permanently sealing it up. That pressure has to go somewhere....

[Fierofool]

If you can get the studs out of it, a hard sanding block can be used to flatten the surface.  It would also show the low spot after a dozen or so passes.  Once you have an even finish across the surface, try a new gasket.  If it blows, then use some J-B WELD
Series ExtremeHeat, Epoxy Adhesive, Jar, 3.0 oz, Gray, 1 hr Work Life.  It has a temp range of 0 to 2400 F.  Put a thin film on the manifold, install the EGR base, tighten it down and let it cure.