cracked upper

[roho94Z]

has anyone expierenced a cracked upper intake in not one but two areas? I had to have mine welded, used is hard to find and GM wanted to bend me over, no recourse. It was running extremely erratic at cold start, when warmed ran fine. No S.E.Light . After repair still runs a little rough but better than it did. only odd moment was after it sat for 4 days when started it jumped up to 3k plus RPM and never let up. Drove it to work that way, didn't need to give it gas... cruise control without the control. any clues??

[Coyote_Rage]

I have a 91 upper if you want. I paid 40 for it it the local yard. 40 +shipping and its yours.

[d.o.h.c]

Your manifold should not crack. They are cast aluminum, but unless you over heat the car alot there should be not problem. And if you got a bad manifold, which I doubt, welding it back up is a bad idea. because weather you like it or not that manifold will never seal again unless you remachine the surfaces. Where did it crack?

[roho94Z]

the first crack appeared on the left side of the casting plug, jb'd it and it ran fine for about three months. crack reappeared and after cleaning area again and repaired again problem remained. pulled upper intake to identify problem and found second crack 3'' long on bottom of intake. had em both welded by local head and block shop guy. cant find any evidence of leak in weld areas, carb cleaner sprayed in areas results in no change of idle.

[MONICAZ34]

hmmmmm... thats nuts