Anyone know what might have caused this? Only thing I could think of is it was installed incorrectly and eventually a vacuum effect caused it to disfigure.

Pics of what the problem was...maybe it'll help someone else on here.

Notice the edges of Cyl 1, 2, 5 & 6?


Close-up of 1&2


Close-up of 5&6


This post spawned from my other thread where I was having major idling issues and fuel smells.
http://forums.maxima.org/showthread.php?t=372554

 

WTF?? Did you use the recommended tightening order and how much torque did you apply?

EDIT: You might have installed it the wrong way. When installed the arrow on that tab should be pointing to the drivebelts.

 

They were definitely pointing towards the drivebelts. No doubt about that. They were torqued correctly too.

Only thing I am not sure of is if the whole thing was sitting flush with the manifold around all the bends.

...it must have been all that power I've been utilizing.
lmao

 

Looks as if the manifold was overtighted. I use 35 foot pounds on the manifold.