So...ont eh 2005 Park AVes form the factory they were still using the UIM with the stove pie touching the plastic ???

as far as i know. there may have been different styles at some point on one car or another but couldn't tell ya which one. all the series 2 motors had the plastic UIM that i know of

The L26 Series 3 motor I believe got the aluminum upper intake to address the issue of the plastic one cracking all the time. I think the first instance of this was in 2004 at least in the grand prix world. In my L36 on my 02 Grand Prix GT I ended up cracking the upper plastic intake. I'm glad they finally did something about that in the upper years.

I know.. just saw this...

Around 2000 the smaller stovepipes began showing up. It depended on build dates and when GM ran out of the previous versions on the assembly lines. This smaller stove pipe didn't fix the issue though. It helped a lot.

The L26 or S3 motor began in 2004 in W body cars. It is possible to retro fit it, however the cost of throttle body adapters etc makes it less desireable in my opinion than simply blocking the coolant ports to the TB. By blocking those ports, you'll never have the coolant near the EGR stove pipe area and therefore it won't fill the motor with coolant.

FWIW Colin.. some of the S1 manifolds were plastic and some were metal. However they are both so different from the L36/L26 S2 and S3 that they can't be used on the motor.

Bill, my question is this; If I buy a 2004 or 2005 Park Ave will I get the smaller stove pipe ? And will it still be a plastic intake ?? And will I get the metal LIM gaskets ?

i have a side question about the uim. my 92 pa shoots steam from under the uim (where it meets the block so to speak) and a dribble of coolant on the drive way every morning. how long until i really have to replace this. i dont have the time to do it myself or pay a mechanic. my father keeps telling me yo use bars stop leak, which im against. so any suggestions.

this new bars stop leak says its safe to use, and for intake manifolds..

I'm unsure about the 04/05 PA. Being a C ?? body they should have still retained the L36 motor. This supposedly has the smaller stovepipe, which is no guarantee of no problems. The best way'* to check.....

Went to Rockauto and looked at the TB gasket. About that time I remembered, if the car is drive by wire, that'* the new UIM. Therefore based on the 05 PA TB gasket, I would say it still has the plastic UIM.

Not sure if I can be of any help, especially since this thread is a tad old, but I'll try since I hate to waste knowledge, especially since I recently I have learned a lot about the UIM & LIM for 96 and up 3800 Series II
I am not sure when, but I did hear GM came up with a first, and second design LIM Gasket, the second one is supposed to be the best from what I have learned, felpro makes a decent LIM gasket, but I prefer GM parts myself.
You can get a UIM that has a better design, the EGR stovepipe port has a steel bushing in it to protect it from heat a bit, it also comes with a reduced diameter stovepipe, a tip for putting it into the LIM, use your old stovepipe after you remove it of course, it should fit over it better then the deep-well socket method.

If you want to know if the car you plan to purchase has an aluminum gasket, just get a multimeter, and set it to Ohm, then touch only the gasket, you should be able to see a tiny bit of it, enough to test, it should show you 0 resistance, is so then you know the gasket is not plastic.

So far the best parts for this repair I've found are below, the LIM gasket is GM'* 2nd design.
http://www.ineedparts.com/auto-parts...kit-17806.html

If anybody ever buys one of these cars with this possible issue, and want to fix it themselves, the repair is actually not too hard if you have a few tools, I am by far a mechanic, but with the net & a good AllData manual, I was able to get all of my stuff removed, and I'm in the process of putting it all back together.