I just got myself an 02 Grand Prix, and I've read up quite a bit on the UIM issue and the gasket issues. I'm looking for some advice now on what to do next, and I thought that maybe some of you wiseguys would know My dad thinks that I'm nuts for getting car advice from a website, but I consider myself a resourceful gal

How far should I take the mods, since my beast will be under an extended powertrain warranty for the next 3 years? First thing I intend to do is flush the coolant, put in some Prestone Longlife, swap out the radiator cap from the OEM, and put in a 180 tstat. My new car has 46,000 miles on it, and I haven't checked yet on the date of the UIM manufacture. My guess is that it'* original.

I got the warranty to protect it from catastrophic failure. But if I could protect the UIM from failing without voiding the warranty (or dumping a whole lotta money into it for preventative stuff), I'd be happiest. What do you guys thing?

Well first of all, I'm sorry we all missed your post until now. Secondly, I can understand your Dad'* trepidation regarding advice from a website, as there are plenty of sites that spout out info without backing knowledge or that do not care for the welfare of the members. THIS IS NOT THAT KIND OF SITE!

As you probably already know, the owner and the admins here are very serious about providing valid advice based on experience or factual information that can be substantiated.

As for the light mods you are planning so far, there should not be any warranty worries. So far, you are on the right track. Most importantly, you are smart enough to do your research up front and and that is a big part of the battle.

IMO, if you do regular oil changes, check your fluids regularly, change your plugs and wires when it'* time and pay attention to what your car is telling you (I.E. listen to it run, note hesitations or misses, strange noises or feel anythin odd), you are already doing what is necessary to keep your car running for a long time.

I am personally not a proponent of changing the UIM/LIM gaskets just "because". Your car will almost always give you some indication that something is going wrong with enough warning to allow you a repair before real problems can occur.

If it were me, I'd go somewhat light on too many mods until teh warranty is up. I am assuming this is your daily driver and as such, it can be a very enjoyable car without doing anything radical to void the warranty.

Anything you can do (like the t-stat, coolant change, etc.) like you have planned should help the UIM.