Highlanders was replaced by his dealer at the time it went the first time around. Probably a Delphi.

It honestly scares me when I think of the weight on these things..they really weight almost nothing.

Thanks for the summary Don. I had seen a lot of this info here in bits and pieces, but this kind of summarizes the situation.

Regarding other mfgs using the composite. It'* true. An example is the Ranger 3.0 that Bill just brought up today. Ford changed that intake in '98 to composite. Lighter, but no way to polish and port for more breathing (unnecessary for boosted folks, lol).

sorry i dont know which uim i had but just sounding of that i am yet another bonnie owner who had both UIM and LIM replaced. :( but its back and im enjoying it now....just too bad i didnt preempt the failure like all the others out there....damn my laziness.

anyway on to the class action and petition polled earlier here...anyone ever here on that thing? im 10000 something for the petition and im sure the class action has a large amount of emailers

So is there less chance of the 3800 II'* made in 1999 or later failing?
I think the manufacture date on my UIM is 3-20-99, real close anyways.

I look forward to it'* failure like I look forward to having a tooth drilled.

There'* no way of ever really knowing when the change occured - I've talked to the people that worked there, and it was one of those changes that was phased in... so I don't think there'* much chance we'll ever find out what day they started using the reduced diameter stovepipes.

Anyhew, re: dorman units, they'll fail, just the same - it'* just a matter of how long they last before they do. There'* a good chance that it'll take so long for them to fail, it won't matter anyway - but with this particular design, it'* really only a matter of time, unless the upper is made of some different material than what it is right now.

And yeah, it'* kind of a funny design, but the composite upper is a very popular design - not just with GM. It'* easy to mold, and gives super smooth air passages, increasing volumetric efficiency. The problem isn't so much with the composite as with having the egr and coolant so close together, in a dirty intake.

I wrote a paper on the subject (sorry, can't post it) for an internal combustion engine class final paper, and the basic conclusion is that with the current design, unless you remove the coolant, or change the material, any other type of fix can be nothing more than a band aid. It doesn't matter how large or small the egr stovepipe is, because it'll still get filled with gunk from the EGR and PCV eventually - and when that happens, heat transfer is no longer convection, it'* conduction. That wears down the composite... and leads to failure.

So unless a sleeve comes out that fully protects the coolant passages (that would be kind of cool, but I don't know that it can be done right), the only way to truley avoid UIM failure is to change the material (i.e., L26 mani).