I recently posted about the lean running our 2011 XF 5.0NA was suffering.

Well, I got the air/vacuum leak down to "under the manifold somewhere" so I bought a new throttle body gasket, and a new set of intake gaskets. I thought that I would smoke test the entire manifold before I put it all back together with new gaskets etc in case I was only to find out that the leak was actually something else.
I blocked up the inlets and throttle body opening with wood backed with rubber as a gasket. Sealed off a couple other holes with duct tape and smoke tested it.








I guess it's hard to see the smoke here, but there's a crack in the "groove" in the manifold.

Ugh, now I guess we need a "new" manifold, trouble is - is this a common issue I might find with a used manifold?

 

The manifold is made from PA66 nylon. I am going to repair it. I have nothing to lose by trying.

I think I'll try stop holes either end of the crack, a partial groove out (not all the way through), degreasing with IPA, hot staples and either fibreglass and matting or JB weld plastic bond. I need to do some more research on fiberglass vs glue.