This every time returning problem can be tackled by putting one
more bellow or a piece of flexible exhaust pipe in the exhaust.
i had this discussion before and they say in a y pipe there is
a bellow ,but there should be one more but than in the first part
of the y-pipe.
i have done this in a stock exhaust.
today i passed the 200000 mile on the odo and the max is still
going strong.
happy cristmas to everyone from ninezeromax out of friesland.

 

Friesland?
Een Maxima bestuurder uit Nederland?

John

 

yes, that should help the problem.

the biggest problem is the heavy stock Y pipe is hanging on all these weak exhaust studs. when you floor the car, the engine jumps around in the engine bay, causing the rest of the exhaust to pull on the y pipe. without enough flex junctions in the Y pipe, this obviously pulls on the exhaust manifolds and thus snaps the studs....
We've known that's the problem for a long time, but I never thought of simply adding another flex section to the pipe to fix it. Good thinking!

 

yay! that gives me at least another 77K miles...hopefully

 

I always thought the problem was the manifold itself expanded and eventually breaks of the studs off. You note that mostly the stud on the ends break.

 

yes you are right expansion by heat is the biggest problem.
but with an extra bellow there is more expansion possible.

 

Ja een nederlander met een van origin canadese maxima ,waarschijnlijk
de enigste die hier in nederland in deze versie rond rijd.
je nederlands is perfect.hoe lang zit al in de states.
peter

 

20+jaar. Echter geboren en getogen in Haarlem.
Veel geluk met je Max. Het is een fantastische kar.

John

 

Given the extent that my manifold was warped when I took it off, I think that the reshaping of the manifold over the years snapped the stud. I had to have it milled back into shape.

 

Actually, Bryan, I think it's the lack of studs there that caused yours to warp. when the manifolds get that hot, they get fairly soft, and the studs are enough to hold it in place. if not, it'll pull away and warp when the engine cools off.

One thing to note on that is how the noise (usually) goes away when the engine warms up. that's because the metal is in it's "relaxed" position at the high temps, and when it cools, it cools off unevenly, causing the warpage.

 

You're probably right. My noise worsened and eventually never went away and was always extremely loud after awhile. The guys at the machine shop were surprised at how much it was warped. I should have taken it easy on my car while they were broken - oh well.

 

i think the construction of the manifolds and the y-pipe is too
stiff ,there is no exspansion possible by heat and this
causes the warp.