Jump to content
Ultimate Subaru Message Board

Cracked intake manifold at Flange!


Recommended Posts

I've had my intake off for weeks and had cleaned it, painted it and made 8mm phenolic spacers. Today, while torqueing down the flange bolts (new longer bolts with antiseize) I heard the unmistakenable "ting" and saw that the flange bolt closest to cylinder one by timing cover had cracked! I was torqueing to just 20 foot pounds when this happened and was torqueing in sequence. WTF! Is this common? Should I have it welded or just throw away and find a new intake? Some days . . . . . grrrrrrrrrrr

Link to comment
Share on other sites

Do you have gaskets on top of and below the spacer? Or does the spacer use o-rings?

Did you work up to 20lb in steps or just start torquing at 20?

 

Torque spec looks to be only 18lb for the ej22. That could vary if you have a different engine.

Edited by Fairtax4me
Link to comment
Share on other sites

You can't torque to the same spec with multiple gaskets. They crush more on the edges and will cause the manifold to bend and crack.

 

 

You need to remove one or both sets of gaskets and use silicone RTV or anaerobic sealant on the flange.

 

Remove the manifold, if the crack is not through the intake runner, you can use JB weld to re-attach the broken peice. You'll have to clean the paint off of the area around it and be sure to pu the manifold on a perfectly flat surface. Use a large clamp to hold the peice tight to the manifold.

  • Like 1
Link to comment
Share on other sites

You can't torque to the same spec with multiple gaskets. They crush more on the edges and will cause the manifold to bend and crack.

 

 

You need to remove one or both sets of gaskets and use silicone RTV or anaerobic sealant on the flange.

 

Remove the manifold, if the crack is not through the intake runner, you can use JB weld to re-attach the broken peice. You'll have to clean the paint off of the area around it and be sure to pu the manifold on a perfectly flat surface. Use a large clamp to hold the peice tight to the manifold.

Thanks, somewhere, I was advised to used two gaskets when going with the phenolic spacer . . . I will pull intake tomorrow to see flange crack, I have a feeling that piece will come off in my hand when I remove . . . JB weld? Really? I know the stuff is strong . .

Link to comment
Share on other sites

If you do it right it will hold well enough for maybe 12-15 ftlbs. That will be plenty if you use RTV between the spacer and intake.

 

I don't think I've ever even used a torque wrench on the manifold bolts on these. The value is so low I just snug them up with a ratchet.

 

I've had plenty of other aluminum manifolds break. Older GM v6s (2.8,3.1,3.4,3.8) are especially bad because the bolt hole castings are thin and the design of the plenum is asking for problems when torquing the bolts. I use a coat of copper gasket spray on those and just snug the bolts up.

 

 

I would go with anaerobic sealant both on the top and bottom of the spacer so you can bolt the manifold down onto a flat surface so it won't flex when you tighten the bolts. The sealer will make its own seal, so the torque spec will be less important.

  • Like 1
Link to comment
Share on other sites

If the ear is broken clean you can fix it. Not recommended buuuuut......

Go buy 4 1/16" roll pins. Drill small holes 1/16" on each side of the bolthole. Try to space the drilling midway on each side. Clean the crap out of both the manafold and your drilled piece. Mix jb-weld as per instructions. Apply to both manafold pieces and roll pins. Carefully tap roll pins into drilled holes. Cut flush after Jb-weld has set. You r good to go.

You but 4 pins because your likely to bend the first one.

Link to comment
Share on other sites

The outer ear cracked on the intake in my ej swapped hatch i just cleaned it with a wire brush then applied jb. I didn't unbolt it after it cracked since i could see it was partially cracked so i just cleaned then applied. I'm eventually going to replace it but that will be when i pull the engine for a frankenmotor. I have about 2500 miles with no problems with the jb weld though.

Link to comment
Share on other sites

Please sign in to comment

You will be able to leave a comment after signing in



Sign In Now
 Share

×
×
  • Create New...