What causes exhaust manifold bolts to break? on 2008 Ford F-150

Does a warped exhaust manifold cause the bolts to break or does the bolts breaking cause the manifold to warp? We are have an issue with the warranty department.

by in Green Bay, WI on November 14, 2012
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2 answers 2 comments
ANSWER by , November 14, 2012
Defective materials or improper assembly.
COMMENT by , November 14, 2012
Wonder what motor this thing has?
COMMENT by , November 15, 2012
It's a gasoline/green jelly hybrid I believe.......never mind....
ANSWER by , November 14, 2012
repeated heating and cooling