My Jimmy was leaking coolant from a pushed out LIM gasket, but my mechanic also noticed the starting of a small crack in the manifold. He said it wasn't leaking out the crack but I should keep an eye on it. Just curious if there is a better aftermarket LIM to go with, or if the OEM one should be used. Either way, whats the part # for the OEM one?

 

Your best bet is going to be a junkyard pull... A new OEM peice is going to be crazy expensive.

And are you sure that the LIM has a crack in it and not a scratch... These things are BEEFY!

 

I would be very surprised to see a crack in your LIM, as Kyle stated, the LIM is a big hunk of metal and not prone to breaking too easily short of running her dry and overheating her to the extreme. I would be more suspect that there may be some metal pitting happening, which you can rather easily overcome with a little gray RTV sealant and new gaskets. Good Luck.

 

Positive, he showed me the crack and its right near one of the bolts holding the intake down. If you tighten it the crack flexes....he said a new LIM would be $400...sheesh! luckily its not leaking so he didn't tighten it as hard as the other bolts

 

You need to find a new mechanic if he tightened the intake bolts enough to crack the LIM. Those bolts only require 11ftlbs max torque (27inlbs 1st pass, 106 inlbs 2nd pass, 11ftlbs final pass).

With that said, I don't think that a crack near a bolt will lessen the reliability one bit. The gaskets seal up around the actual passages, not a full face seal like old paper gaskets were.

 

No, it was cracked before he took it off, he looked at it first and noticed it before touching it