I've got a 2002 3.4l base model (bought brand new) with 86k on it right now. At 60k, I flushed out all the Dex-Cool and replaced it with the green "mixes with anything" stuff (from Wal-Mart). I had heard about the Dex-Cool breaking down (or possibly eating the gaskets), so I got it out of there just to be on the safe side. In October of 2005, at 67k, I got my first "Low Coolant Level" message in the message center. At 78k I had to add some coolant (maybe as much as 1 Qt.). At this point, I ordered a new Coolant Level Sensor in June 2006, but never ended up installing it. Instead, I pulled out the old one and cleaned it and this made the message go away for a while. At 80k, my water pump leaked out the weep hole and I replaced it (don't know if this is related in any way). At 82k, the "Low Coolant" message appeared again. At 85k, it appeared again. All this time, I've been religiously changing my oil every 3k miles because I've been concerned that I might have a leak. Well, now I'm convinced I've got a leak.

I think I can do this repair myself. I'm not a mechanic, but I've done just about everything short of rebuild an engine. Although I've replaced half axles, brakes, various motors, timing belts, radiators, etc., I'm guessing this will be the most challenging repair I've ever done because I've never dissassembled the engine in any way.

Here are my questions:

1.) What is the kit# I should be asking for at the dealer?
2.) Is the UPPER manifold gasket, LOWER manifold gasket, or both that is/are defective?
2.) What exactly will be in the kit? 2 gaskets, 4 gaskets, # bolts, etc??
3.) How do I know I've got the "revised" or "updated" kit and not an old kit that's been lying around the service center?
4.) What special tools do I need? In addition to my standard Craftsman tools, I've got a Craftsman "click-type" torque wrench. Will this be sufficient? I've never actually used it because the scale is always too high for the low-torque uses I've encountered in the past.
5.) I have the Chevy manuals. I always buy the manuals right after I buy the car. Is this procedure OK, or was there a revised procedure released with the kit?
6.) What are the critical steps in this repair? Example: cleaning off the old gasket material, torqueing down the bolts, avoiding mixing up parts on re-install, etc...

I had the same thing happen at around the same mileage but with a 99 Cutlass with the 3.1 liter motor. Same family of motors/gaskets. I didn't feel competant enough to try it myself but had a local trusted mechanic do it so I can't really answer your questions. One suggestion though. Change the plugs while you have the thing apart as it will be much easier to get at the 3 on the firewall side before you put it back together.

Dave

I have had this exact same problem with my '02 base 3.4L. Although it sounds like you've had a lot more problems with your car. I've replaced the thermostat twice to fix the leaking coolant. The gasket warps slightly and visual inspection leads most people to think it is fine. Replace this should fix your problem. The good news is it is easy to get to and very inexpensive so if I'm wrong you won't be out of a lot of money. I really doubt this problem requires rebuild especially with your mileage. My '02 has 132k and short of the coolant and just replacing my CV axles last weekend I have orignal equipment and still going strong.