Hah, on my third Upper intake at 175K. The first one lasted 7 years though.

 

The main thing is you got to catch it FAST and FIX it!!! If you Keep Under the hood clean your gana catch it and IT IS GANA HAPPEN!!!

 

thx for the update and replies fellas - as I'm at 206k miles and just over the 7 year mark I'd have to assume I should consider getting the upper gasket replaced. I'd rather do it now then waste an otherwise strong motor.

lol - I got the resonator replaced saturday and the guy remarked "how 'bout that its got over 200k miles and its not a toyota"

 

If you are doing the UIM gasket yourself, you should look into going all the way down to the LIM and replacing those and your valve cover gaskets as well.

 

^ agreed... also, get a whole new upper intake manifold from dorman or a metal one... there are write ups all over the place available for the metal conversion. The standard plastiic one tends to break at the stovepipe where the egr valve enters it. Gm fixed the problem later... just didn't bother to tell anyone about it in the first place.

 

The Metal Conversion is usually called the L26 UIM Switch or similar, since the L26 is the 3800 Series III motor.