Cracked 3.1L (M) UIM....

[Sprawlins]

I recently payed some friends to do a tune up and cleaning of my intake system, plugs, and suspension. And to my surprise I started up my car this morning to hear what sounded like a vacuum leak... It was....

I have a crack around the bolt on the left side closest to the front bumper. I don't really feel comfortable just trying to seal it up.



I would like to replace it, and i've heard that the 3.4 UIM swap is possible. Would I have to replace the LIM as well? And Where can I find these in a newer condition, possibly even performance if available?

[bszopi]

Since you have the older, small-port 3100, then you would need to swap out the lower as well if you wanted to go to the 3400 (or larger port 3100, which is the same) upper manifold. For performance ones, check out the WOT-Tech banner at the top of the page.

[Sprawlins]

Thanks! very helpful. going to be another 800 to get me where i want to be lol

[Roadbastard]

dang I have a crack in the exact same spot except it's the bolt piece that broke off.

[Superdave]

The usual cause of this is re-using damaged gaskets, seen it a lot on these engines.

[Sprawlins]

My gaskets are brand new. I think one of the guys that worked on mine torqued it by hand and in the wrong sequence.... But then again, I just loosened all of the bolts, sealed the crack, tightened it all down, and I got another crack of the same type above #2... I was driving home and I turned on the A/C & I heard it crack... So far I'm not getting near as much leakage as the first crack, but still.... another crack....

[Superdave]

weird... I'd pack it with JB weld and hope for the best. Even a stock large port LIM and UIM would be an improvement over the small port stuff, probably $50 or so at the junk yard if you pull it.



i never torque the UIM, just snug it down.

A local guy cracked every runner on his 3400 UIM about a month ago following the torque specs, he tried RTV to seal the cracks but ended up just getting a new one... which he cracked as well.