I've been chasing a vacuum leak for months on my '03 2.5 sedan. I've pulled the intake and lower manifold 10x, replaced the upper and lower gaskets twice, IMT O-rings, pcv hose, new injector seals, throttle body gaskets, etc. Literally everything. Long story short, I finally bought a smoke machine and it showed me that it's leaking from the two ports on top of the manifold. I had already replaced both lines as well as the inner brass and plastic connections so I was surprised to see them still leaking. What else can I do besides slap silicone on it?

 

Would a smear of heavy grease be an alternative to silicone.
As long as it is dense enough to hold its form against the vacuum and heat, could be better than silicone as you can still easily release the fitting afterwards.

 

What codes are u getting

 

An idea: Use Plumber's tape around the vacuum tube-ends, before you place them into those brass/plastic connections.