Deleted 6.7 blowing manifold gaskets

[smokinpigeon97]

Hey guys I got a 6.7 that I replaced the exhaust manifold before I did my deletes due to it being cracked and gasket #6 leaking, put new manifold and gaskets torqued nuts to 35 ft lbs about a 3 months ago and just last week found gasket #2 blown puking black and damaged the manifold so replaced all gaskets machined manifold and mounted and retourqued everything... Can anyone tell me why it's doing that so I can make it stop

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[Wildkarrd RRD]

@Polaraco, any ideas? Only thing I can think of is the head isn't true on the mating surface. I'm assuming when the manifold was machined it was trued up.

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[Polaraco]

Are the bolts loose?

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[F350Cummins]

stock or aftermarket manifold? what mods besides deletes?

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[DRD]

Just my 2 cents.

Something isn't right for sure. If your manifold has been machined and trued, then take that out of the equation. Like Drew said, make sure the mating surface on the head isn't gouged too. Make sure your fasteners are not coming loose on you like Steve said. Also be sure to use Cummins multi layer exhaust gaskets when putting it back up. The multi layer gaskets help take up the slack left by slight imperfections. After this point, might want to check on the turbo's operation. If you use the exhaust brake alot and the actuator is out of calibration, it could close the turbo up too much and raise the back pressure too much as well. If you have a back pressure gauge installed, you don't want it go past 65 psi very often when the exhaust brake engages. I've seen mine hit 80 psi under hard braking but that's only when it engages from a high rpm.

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[Polaraco]

I have to look it up, but 35 Ft Lb sounds a bit light

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