:( might as well add my '02 to this thread: It has 44k miles on it, and the UIM is leaking coolant. -same place, under the TB, down onto the trans housing, and onto the garage floor. I discovered it a couple of weeks ago, and re-torqued the two long bolts near the TB. Well, that only lasted for about 10 days, and now it'* leaking again.

I have the new UIM in the garage, and am now just waiting for the time (and ambition) to replace it. Like others, I have to suspect that maybe just replacing the gaskets would fix it. BUT, I have to say, with the price of just the gaskets being so high, and even worse, all the work involved in replacing them,,, it makes me think the only smart thing is to replace it all, with the new aftermaket unit which includes the new gaskets. Also, the aftermarket UIM is supposedly made of better plastic, etc etc. (-personally, I have to wonder,,,)

And for all those good "motorheads" that remember my other replies related to these UIM failures, I have already been into this '02 once. -replaced the LIM gaskets, and did the "sleeve trick" on the UIM. BUT LIKE A STUPID FOOL I re-used the UIM gasket, (as well as the UIM) when putting it back together. I thought the gasket looked good enough, and besides that, it wasn't leaking before :(

I have learned my lesson: Always use a new UIM gasket.

WHICH brings up the next question: For those of you who have purchased the UIM gaskets separately from the UIM, where did you get them ?? -and for what price ?? (I just priced them at NAPA today, and YUK !! -TOO EXPENSIVE

that sucks!! have fun!! but what is a UIM??? i just used some Hight heat RTV type sealant and i havent had any problems since.

UIM is the acronym for the Upper Intake Manifold. I don't think that 57 Thunder has a failing upper intake, it may be where the throttle body makes up to the uppper manifold. There was a recall to replace the fasteners for the TB, the gasket and then add sealing pellets to the coolant to resolve that problem I thought.

how much is a Aftermarket TB and UIM??

You can buy the aftermarket replacement UIM from 1 A Auto (www.1aauto.com) for right at $150 delivered. I think you can even find some other on-line sources somewhat cheaper. -I even saw them on ebay at $119, as I recall. And the last time I checked NAPA, it seems to me their price was still over $200. :?

Anyway, I agree that it is doubtful that I need to replace the UIM on the '02. When I sleeved it, there was no deterioration, and visibly it looked just fine. So probably all I need to do is just replace the gasket.

I'm still hoping to find a souce for the gasket, somewhere close to a reasonable price,,,
-will check the chevy dealer tomorrow,,,

alrite once i have it .... its what 3-4 bolts to take off and put on??? do i need to get a new gaskit? or can i re-use the old one?? or does depend on what it looks like?!?

:? Say, Nitro, I'm thinking that you may still may be somewhat unclear on this topic.

I just went back and re-read all three pages of this topic, and it seems to me that it has been very excellently described and documented.

I was going to try to help you out with another reply, but after having gone back and re-read this whole thing, --there is nothing more that I can add. -it has all been said, I think, but if you are still not clear, feel free to reply again !!

-partial update on progress on my '02. It turns out the external coolant leak, as best I can tell, was actually from a failing TB gasket, not the UIM gasket. Anyway, I'm darn sure replacing BOTH of them now.

Say, I installed one of Bill Buttermore'* stainless steel sleeves in a new UIM this evening. Man it is terrific The job went real slick. Without a doubt, I TOTALLY recommend installing one of Bill'* kits.

Bill you get my "gold star award" for your parts
(-and to be clear, I am only using the UIM sleeve on this one, since it already has the GM reduced size tube in the LIM.) But there is absolutely no doubt in my mind, that installing Bill'* reduced tube in the LIM would also be a total breeze. -actually, easier than sleeving the UIM,,

Okay, next update: Got the '02 back together this evening, and am now in the process of multiple cooling system rinse, refill with water, run up to temp, drain, rinse, re-fill, etc etc, -you get the picture. -trying to get all of the pink poison out of it, so I can install the new Prestone "all-color." (-it is a sort of yellow/green, I think)

Also, I FINALLY GAVE IN and installed a 180 degree thermostat too. -A whole bunch of you motorheads out there in "Bonneville Land" will now be laughing, and saying "I told you so" and justifiably so. I still don't think it is a good idea, except for trying to prolong the life of my new LIM gaskets. And one thing for darn sure, if it adversly affects my ecomony or performance in any way, I'll be going back to the 195.

And BTW, the actual source of my external coolant leak, as far as I could tell, must have been at the bottom of the throttle body, and seeping along the UIM gasket, making it look like that was where it was leaking. ANYWAY, I have new gaskets both places now, so here is hoping !!

SO, here is hoping that the combination of different coolant, different LIM gaskets, and the 180 degree thermostat will maybe extend their life :?: --time will tell,,,

Thanks for the update, hope all goes well.